A gay woman who was unlawfully deported from the UK was blocked from returning to the UK after the British government failed to issue her with documentation to board the flight.

The 26-year-old, known only as PN, was told by airline staff that she could not board the flight scheduled to bring her back to Britain in the early hours of Monday, because the Home Office had not provided written evidence of her visa waiver.

The Ugandan national has told The Independent she was gang-raped and has lived in perpetual fear since being sent back to Uganda in 2013. She also talked about the trauma of getting pregnant and having a child, who is now four months old, as a result of the sexual assault.

The British government was earlier this month ordered by the High Court to help her return to the UK on the grounds that its decision to reject her asylum claim had been unlawful, because it was reached by an unfair process which did not give her sufficient time to obtain evidence.

She is one of thousands of asylum seekers whose immigration cases were decided under the Home Office’s “detained fast-track” system, which was introduced in 2005 and came to an end in 2015 after the High Court ruled that it was “structurally unfair”.

The Home Office had booked her onto a flight just after 4am on Monday, but she said that when she arrived at the check-in she was told she could not board without written evidence that she didn’t require a visa – which she had not been provided with. The department said it had been working urgently to resolve the matter and PN was due to board a later flight on Tuesday night.

Speaking to The Independent, PN said: “They said I needed something to prove I had a visa waiver. But the High Commission and the Home Office never told me I needed anything. I had nothing to show from the Home Office. They should have got somebody to speak to the people at the airport, something to show them. I don’t know why they didn’t do that.

“I had to go back home. I haven’t slept at all. I keep asking myself why have they done this to me. It’s giving me headaches because I’m thinking too much. I can’t even eat, I can’t drink, because I don’t know why this has happened.

“I was in the airport, I was happy. I saw the flight. I knew I was going back. Now I feel so afraid. I don’t even want to move from my bedroom. I don’t want to leave. I’m scared people will know who I am. I just want to get out of this mess. I’m tired of it.”

PN, whose full name cannot be disclosed for legal reasons, arrived in the UK in 2011 and claimed asylum on the basis that she was a lesbian and would be at risk of persecution in Uganda. But this was refused and she was removed in 2013 because the Home Office did not believe she was gay.

The Home Office has been ordered to facilitate her return to the UK, but is set to appeal the decision, meaning PN faces the prospect of being sent back to Uganda again if the department is successful.

Karen Doyle, national organiser of Movement for Justice, a group which has been supporting PN financially since she was removed to Uganda, said: “Being turned away from the flight was frightening and devastating for PN. Having to make her way back to her room in the early hours of the morning after hours in the airport full of anticipation and hope she would be safe in the UK today.

“Once again the home office have shown their lack of care and concern for her safety. This latest blow for PN is emblematic of the delays, appeals and blocks the Home Office have put in place ever since the order for her return on 24 June.

“It is not acceptable and the Home Office must do everything they can to put this right and get PN out of Uganda.”

Protests have been staged outside the Home Office in support of PN’s return (Phillip Raymond Goodman)

It comes as more than 400 people staged a protest outside the Home Office building, calling on Priti Patel, the new home secretary, to end the “hostile environment” and deportations.

Lucille from the All African Women’s Group, a self-help group of women asylum seekers and immigrants, many of whom have been detained in Yarl’s Wood, said: “As women, we suffer particularly from the hostile environment because we are poorer to begin with, are often traumatised from rape and other violence and because we are often mothers with responsibility for other precious human beings.