Thousands of customers were hit when the shop closed

About 30,000 customers were affected when Mobile Connections, owned by Bordesley Green-based Dialamobile, stopped trading.

They faced long contracts with phone service providers where they had to pay what was a previously free service.

But trading standards said that in most cases, no written contract existed.

Under the deals, customers would take out a deal with Dialamobile and would receive a bill from the service provider.

'No contracts'

Customers would then take the rental bill to Dialamobile which would give them cash back.

However, since the firm stopped trading, customers had had to pay the bill from the service provider.

Chris Neville, of Birmingham Trading Standards, said: "Customers can terminate the agreement that they have with the airtime company if they haven't got a contract with that airtime company.

"We think that in 99% of cases there aren't any contracts in existence. They should write to the airtime company giving a month's notice of their intention to terminate their direct debit and at that point stop paying.