The first flaws in the new immigration scheme for EU citizens who want to remain in the UK after Brexit have been exposed after a couple who live in Oxford were blocked from getting a flight back from Turkey to the UK.

Arthur Vissing, a Danish citizen, and his Turkish wife, Ezgi Vissing, called on the government to urgently review its procedures to allow those who hold residency rights in the UK to travel unhindered.

Their ordeal started last Thursday at Istanbul airport when British Airways told them a number of times Ezgi did not have the right paperwork to get on the flight.

It took 24 hours, seven phone calls to the Home Office and others and the intervention of their Liberal Democrat MP, Layla Moran, before BA let them on the plane.

Non-EU spouses are entitled to travel and reside with their EU national husband or wife in another member state under EU freedom of movement laws but, under the UK’s post-Brexit plans, EU citizens and their family members must apply for “settled status”.

BA said it was only following instructions from Border Force in the Vissings’ case, but Ezgi said she got a blank look or negative response when she explained the new immigration system in place for EU citizens.

In a tweet posted as she was trying to get the situation resolved, she said: “I was asked time and time again if I held a UK visa. I said I held a pre-settled status. The officer, then, seemed puzzled by the very concept. I was advised by the @ukhomeoffice that my status would be checked on the screen automatically.”

She claims she was threatened with removal from the airport when she asked to see a manager to explain why she thought the check-in staff were wrong to refuse her a boarding card. “I got a very harsh reaction,” she said. “So we sat on the floor making phone calls to the Home Office to try and sort this out.”

Overnight, they tried but failed to get proof of their rights from the Home Office, leaving them concerned that Ezgi would not be able to get back to Oxford, where she has lived for six years.

@the3million, @ukhomeoffice's "EU Settlement Scheme" doesn't work. I am NOT allowed to cross the border in Turkey although I DO hold a pre-settled status. @British_Airways, advised by the British Consulate in Istanbul, is refusing to use the online verification system. — Ezgi Vissing (@EzgiVissing) May 10, 2019

On a scale of one to 10 in terms of stress, Arthur put the experience at nine. “You feel like you are losing the most fundamental thing in life, the right to have a family life, the right to have the person who is closest to you to live in the same country as you,” he said.

Ezgi said she found the 24 hours very distressing. “Arthur managed it better than me; he was trying to make me laugh, keep my spirits up. I was in tears most of the time. I would not like to go through it again and would not like any EU citizen or their families to go through this,” she said.

The campaign group for EU citizens, the3million, said the case was proof that EU citizens needed physical documents and not a webpage on a Home Office site as evidence of their rights.

“The Home Office is promising us a lifetime of worries by refusing to issue EU citizens who successfully applied for settled status a secured physical document,” said Nicolas Hatton, the group’s co-founder. “It would reassure the elderly who don’t use online services and those who worry about returning to their home in the UK from a holiday, but not able to because the system is down.”

Ezgi had been so wary of having to prove her rights to travel before the trip that she had not left the country since the referendum three years ago. It was only after the government announced the settled status scheme for EU citizens and their families that she felt it would be safe to go abroad.

She had hoped to travel to Istanbul for a friend’s wedding and carry out research for her doctorate at Oxford University and had been assured in telephone calls to the Home Office that her new ID would be released on time for her trip on 2 May.

As part of the application as a non-EU national, she was also required to have her fingerprints taken in Croydon and the first appointment available was on 9 April, which is when things started to go awry. With just a week before her flight, the Home Office told her she had been “downgraded” to pre-settled status for people in the country fewer than five years.

“This was very odd because I had been in the country over five years but also because they said they would reset the clock and it would be another six to nine days before they would release the pre-settled status,” she said. “I don’t think it was a coincidence they told me this on 9 April, the day I had my fingerprints taken.”

They made four calls to the Home Office before travelling and took a copy of their marriage certificate with them to prove their rights, but to no avail.

“I offered the check-in staff the printouts of the gov.uk webpage with a link to my case. They said they wanted to help me but they couldn’t do anything. They said this was the advice given by the liaison officer in Heathrow and by the British consulate,” said Ezgi.

Nicolas Rollason, a partner at Kingsley Napley law firm, said the Vissings had come up against a “longstanding” difference in treatment of family members of EU nationals from countries who require visas to visit the UK and those who do not, such as US citizens.

Americans can board flights and be “re-admitted at the border as a matter of course” but airlines often refuse other non-EU nationals “even if they have the required proof of the status as an EU family member”.

Rollason added:“The Home Office should work more closely with the airlines and ensure that all carriers have clear lines of communication with UK immigration for getting pre-boarding clearance and help travellers on their journeys in these circumstances.”

A spokesman for BA said it was Border Force and not the airline that issued the instructions to prevent Ezgi from boarding the flight.

The Home Office said the individual had travelled without documentation and had been advised to apply for a biometric card. Ezgi pointed out they had done that and it was that application that appeared to have caused the delay in getting settled status.

“We have been able to assist an individual with the right to enter the country, but who did not have the necessary documentation with them to travel to the UK,” said a spokesman.

The Home Office said it had given as much help as was possible and at the time of travel Ezgi’s application was still pending. She did not travel with a biometric card, as advised by officials, before her outward journey, the Home Office added.