It requires a military level of discipline to live most of your life in Heathrow airport. Gbolagade Ibukun-Oluwa, 59, has been homeless since 2008 and for the past five years has developed a routine that sees him spending several nights a week in the cafes just outside the departures area. He arrives between 11pm and 1am, as day staff are replaced by the night shift, rotating between a Caffè Nero in Terminal 4 and a Costa coffee shop in Terminal 5, where the workers know him and offer him a cup of hot water. If flights have been cancelled and the cafes are very busy, he takes a bus to a 24-hour McDonald’s on the airport slip road, and waits there until dawn, occasionally managing to sleep for an hour or two in his wheelchair.

In the past, Heathrow security have been hostile, calling the police, who would put him in a van and drive him beyond the airport perimeter, where they would drop him and tell him: “If we ever see you there again, you’re in big trouble.” But that aggressive approach has stopped, and mostly he is ignored by passengers and staff; at a glance he looks like any other traveller, his belongings tidily packed into a few bags. “I have a routine to arrive as late as possible and to move on as early as possible,” he says. “They don’t bother me. They’re used to people waiting all night for a flight.” For all the hassle, the airport is at least warm and safe.

During the day, over the past few months, Ibukun-Oluwa has been working to untangle the immigration problem that has left him homeless for years, trying to persuade the Home Office that he is not an illegal immigrant. He arrived from Nigeria as a 20-year-old student in 1981, has lived here continuously for 40 years and is one of a number of people affected by the Windrush scandal who are still attempting to get help almost two years after the government first apologised and promised to fix its mistakes.

I spoke to Ibukun-Oluwa at the Caffè Nero by Heathrow Central bus station last Wednesday morning, before he left for another day attempting to track down copies of lost paperwork to support an application for help from the government’s Windrush taskforce. This is the body that was set up to assist the thousands of people incorrectly classified as illegal immigrants and told they were not allowed to work or claim benefits, denied healthcare and, in extreme cases, wrongly detained and deported.

He is exhausted by the difficulty of combining homelessness with the complex task of gathering evidence of a lifetime spent in the UK. “I haven’t slept eight hours together in the last six days,” he says. In 24 hours he had eaten two croissants (which he bought) and a pot of soup given to him by a Pret a Manger worker. “He said it was on the house.” He says the experiences of the past 12 years have changed him. “I am not the person I was. I have been dehumanised for a long time. I don’t know any human being who has gone through what I am going through.”

The Windrush issue will return to the headlines again imminently, with the long-overdue publication of an independent review of what went wrong. This is likely to be published in the next 10 days. The government would like to be able to say that it has resolved the problems that have affected thousands of people. It will make much of the fact that in the past two years more than 8,000 people have been given documentation proving that they are (and always were) living legally in the UK, and will highlight the compensation scheme that has been set up, with an estimated budget of between £200m and £570m. It may be less eager to dwell on the fact that only £62,198 of compensation has been paid out, shared between 36 people.

It is hard not to feel dispirited by the severity of the difficulties that many people are still facing. Two days after talking to Ibukun-Oluwa, I meet Andrew Bynoe, 59, who arrived in London from Barbados aged 12. That was in 1978, when his mother was a nurse at University College hospital in London, and his father had been recruited by London Transport to work here as a bus conductor.

He went to secondary school in Paddington and, after a troubled teenage period, set up a vehicle recovery firm, employing others and paying taxes; later he moved on to other jobs. But with the arrival of tightened hostile environment immigration checks in 2014, he found himself wrongly classified as an illegal immigrant; he was dismissed from a number of jobs because he couldn’t prove he was in the UK legally. Determined to stay in work, he took up a sequence of less suitable jobs until he finally lost his position as a cleaner at a central London Primark in 2015. His bosses were concerned they might be fined £20,000 if they were found to be employing someone who was in the country illegally (despite the fact that he was living here legally). He repeatedly attempted to contact the Home Office, but was told it had no record of him. He got into debt and was unable to pay his rent, eventually becoming homeless last August. He sleeps sometimes on friends’ floors, occasionally on his son’s sofa, in his son’s van, on a London night bus and recently in the stairway of block of flats. He is a regular visitor at food banks, goes to the charity Crisis to pick up soap and toothpaste, and eats hot meals at a local soup kitchen.

I was extremely surprised to discover that he was still homeless because the Labour MP Yvette Cooper had mentioned his situation in a Commons debate on the Windrush compensation scheme on 10 February. The home secretary, Priti Patel, promised to look into the case – but he is still waiting for emergency help.

I have met and interviewed at length about 50 people affected by Windrush problems over the past two years, and each case is disturbing in a different way, but there was something depressing in the detailed summary of his situation that Bynoe sent me. “The psychological effect on me has been massive. In 2014, I lost my hair because of the stress. I would walk the streets because there was nothing I could do. I did not tell a lot of people as it was so demeaning. I had to pick up butts from the street to make into cigarettes. I could not buy my daughter a birthday present. For a year I cut myself off, and my son reported to the police that I had gone missing,” he wrote.

‘The psychological effect has been massive’ ... Andrew Bynoe, one of the Windrush victims, who is homeless Photograph: Anna Gordon/The Guardian

After the government apologised for its Windrush mistakes in 2018, Bynoe applied for and quickly received documentation confirming that he was in the UK legally. He applied for compensation as soon as the scheme opened a year ago, but has received no money and remains considerably in debt because of the period of enforced unemployment. Last August, he was told he was going to be evicted from the bedsit he rented because of arrears. He asked the Home Office for an emergency payment, under the Windrush vulnerable persons scheme (designed for precisely this kind of situation), but this was refused. “We are not satisfied that there is a sufficiently compelling reason to offer a payment or that the circumstances of your request are exceptional,” an official wrote. He was duly evicted and has been homeless for the past eight months. The treatment he has received at the hands of the vulnerable persons unit, which he has been ringing almost daily over this period, feels worse than the original injustice.

Officials there referred him to the housing department at the local council, which said he needed to rent a flat privately, but would have to find a deposit; he applied to the vulnerable persons team for money for a deposit, which it promised to give him months ago, but it has not arrived. Periodically, officials get in touch to ask him for “further evidence”; during one call he was told the request was “being assessed”, later he was told it was with the casework team, then that it was going through “authorisation”, on another day that it was “99.5% processed”; some time later that it was with “finalisation”; then that it was “with`quality control”. On one of these calls to the unit, he told them that he had had enough and was going to kill himself.

“I was destitute; what really hurt me was that every time I called them up there would be a different reason. It felt like intentional torture. I felt crushed and wanted to call it a day. It was raining, my shoes were soaking wet, I had nowhere to sleep and I’d spent the night on a bus; it was the only place to be warm,” he says. Officials kept him on the phone for an hour and a half, and suggested he visited his doctor. But the money still did not arrive. “I’m still homeless.”

He says he finds his situation profoundly degrading, and chose to have an anonymised photograph taken because he feels humiliated at having been forced into homelessness, though no fault of his own. I met him at the flat of his son, Fidel Shelley; Bynoe was so ashamed of his situation that he only recently told him he was homeless.

Most of all, Bynoe is filled with rage at the life-shatteringly negligent treatment he has received from the Home Office. “I think the system at the top is institutionally racist. The people making vital decisions are people who don’t have any connection with normal people. They don’t have to mix with us.”

Shelley says his father’s experience has left him unsettled. “It creates a fracture in my sense of what it means to be black and British. It’s not nice to love your homeland on one hand and see it completely disregard the contributions of your parents and grandparents.”

The causes of Ibukun-Oluwa’s Home Office problems are complex; people’s lives are complicated and the increasingly rigid approach of immigration enforcement has little time for the subtleties. He lost his passport and other documents in 2002 when he was evicted from his flat during an unexpectedly protracted spell in hospital; many of his belongings were thrown away. Although in 2000 he was granted indefinite leave to remain in the UK, for a while he lost the letter documenting it. He was in a Surrey hospital for months after a serious car crash in 2008 with spinal injuries that have left him using a wheelchair; on discharge there were questions about whether he had the right to be in the UK and whether he could receive housing support. It was decided that he was not eligible for public funds, despite the fact that he had worked and paid taxes in the UK for more than 20 years. Since then he has been homeless, occasionally staying on friends’ sofas, spending more than six months living in St Pancras station. A year ago he managed to get sickness payments reinstated, and uses the money to spend two nights a week in a cheap Heathrow bed and breakfast, to shower and sleep properly.

When the news of the Windrush scandal broke in 2018, he was initially unaware that it applied to him, since he had come from Nigeria rather than the Caribbean. He attended a Windrush support session in January at the Black Cultural Archives in Brixton, south London, where lawyers were offering free advice to people struggling to resolve their status. Dawn Hill, the organisation’s chair, has been disturbed by the extreme situation that many still find themselves in, and is frustrated by the lack of government funding to support volunteers’ work. “We are providing support to very vulnerable clients. These cases are so complicated, but we are doing this on a shoestring.”

Ibukun-Oluwa has given the lawyer and Windrush expert Jacqueline McKenzie a detailed account of his employment record since his arrival in the UK, including stints in Mothercare (where he remembers receiving a birthday card from its owner, Terence Conran, congratulating him for his work) and H Samuel, working for the Inner London Education Authority as a football coach, and a long period in an import-and-export business.

McKenzie, who is offering him pro bono help, says: “It’s quite distressing to be meeting new people affected by the Windrush scandal some two years on. Despite finding a letter which confirms that Gbolagade has indefinite leave to remain in the UK, he is still being denied access to housing and other support as he does not have a British passport or a biometric resident permit; he had no idea he needed either after living in the UK for 40 years. Gbolagade has to be one of the most needy people I’ve dealt with and yet he’s been signposted by the Windrush taskforce vulnerable persons team to a charity that simply provide beds in church halls at night.”

A Home Office spokesperson said staff were in touch with Ibukun-Oluwa to try to resolve his situation. “We are determined to right the wrongs experienced by the Windrush generation.” Another Home Office spokesperson sent a similar (cut and pasted?) response in relation to a query about Bynoe: “We are determined to right the wrongs experienced by the Windrush generation.” The spokesman said the vulnerable persons team was in regular contact with Bynoe and “provided funds to help him secure a private property”. When I rang him on Monday morning, the money had still not arrived.

The Windrush Betrayal; Exposing the Hostile Environment by Amelia Gentleman is published by Guardian Faber. To buy for £11.75 (RRP £18.99) go to bookshop.theguardian.com or call 020 3176 3837. P&P charges may apply.