Dozens of families across the UK claim they have been ripped off by an immigration firm based in the Midlands.
The company - called UK Visa and Immigration - sold advice on how to get a UK visa or citizenship, but was recently banned from practising because of the number of complaints it received.
But BBC Inside Out has discovered that another firm with links to the company is still trading without being regulated, which could potentially be illegal.
Both firms deny they are the same company operating under different names.
A dozen UK Visa and Immigration customers have told the BBC they paid more than £1,000 for a service that wasn't delivered.
Some say they discovered the visa application they paid for was never submitted, others say phone lines went dead after they paid the fee and many say promised refunds never materialised.
Ian Northeast, 37, is British but wanted to bring his mother-in-law, who lives in Thailand, over to the UK after her husband died suddenly.
He paid UK Visa and Immigration £1,250 but says that 18 months later, he still hasn't got the visa or refund he was promised.
Mr Northeast said: "It was incredibly difficult, it was right in the heart of a recession, we paid for it on the credit card and as my salary came down, we struggled to pay that back.
"Even now we're still paying back the credit card."
Before being struck off in July 2012, the firm attracted around 100 complaints in just over a year, which made up 25% of all complaints received by the industry's regulatory body during that period.
Inside Out has also spoken to three former employees who worked for UK Visa and Immigration.
Adam - not his real name - worked for the firm during April this year.
He said: "When a customer called up, we were told to put them on hold for 10 minutes, pretend we'd come back from a chat with a barrister and say: 'As long as you can pay today, then we can 100% get your visa sorted'.
"Employees were under pressure to get more money out of the customers.
"I heard customers crying on the phone: one consultant turned round to a guy in his fifties and said: 'Do you love your wife? Well great, so is she worth £1,500?' You wouldn't talk to your dog in the same way."
All three former employees also claim that around April this year, bosses told them the call centre would no longer use the name UK Visa and Immigration, but would operate under UK Immigration Barristers.
UK Visa and Immigration started life in 2010, while UK Immigration Barristers was set up in 2011.
'Time ran out'
The BBC has discovered that the director of UK Immigration Barristers, Nadeem Akhtar, was also a legal adviser at UK Visa and Immigration. Additionally another key worker, Mohammed Kazi, also worked for both companies. He oversaw the day-to-day running of the call centre and training of staff.
The two men admit to working for both firms, but Mr Kazi said he does so as a self-employed consultant.
While UK Visa and Immigration was regulated before losing its licence, UK Immigration Barristers has never been regulated.
It is a criminal offence to give immigration advice unless those giving advice are legally qualified or the company is regulated by the Office of the Immigration Services Commissioner (OISC).
But secret recording carried out by the BBC shows UK Immigration Barristers giving immigration advice through an unqualified advisor, to an actress who posed as a potential customer.
The OISC - which regulates the industry - says it is investigating and has the power to bring prosecutions.
Mr Akhtar, the director of UK Immigration Barristers, has launched an internal inquiry into the matter and says the employee concerned has been suspended.
He said his firm acts as a broker between barristers and clients and does not provide any "legal advice or services to its clients".
Mr Akhtar said: "I use the services of a few call centres to handle all the calls for my company… The call centre has a strict zero policy regarding giving immigration advice."
He doesn't dispute the fact his company is unlicensed but says he was told there is no legal need for it to be regulated.
Ash Shadat, the director of UK Visa and Immigration - the firm which lost its licence after attracting so many complaints - said: "Towards the end of the life of UK Visa and Immigration there is no doubt in my mind that there were clients who maybe didn't get the service.
"That is because time simply ran out for us.
"Once your licence is cancelled you are no longer legally allowed to give any form of advice."
He said he could not pay refunds owed to customers because a third party still had not released the relevant funds, but promised to pay out of his own pocket if necessary.