Mark Smith and Laura Jones (not their real names) hired a Ford Escort from Hertz, paid a cash deposit of pounds 140, and assumed this would be repaid in full once the car was returned undamaged. Ms Jones said: "At no time was Mark told he would have to wait. He was just told he would receive the deposit when he returned the car. But when we returned the car, he was told, 'We have no cash.' Hertz said they gave back cash on a first- come, first-served basis.
"We paid them in cash and expected cash back. They said they would give him a cheque, but then they said they could not issue a cheque until the end of the week." Because of the delay the couple and their children were unable to go on a planned trip to Great Yarmouth.
A spokeswoman for Hertz said: "It is the procedure practised for many years. Customers should be made aware when they rent a car that if they give a cash deposit they may not get it back in cash. We have not had problems before. We are not aware that we are breaching any legal obligations."
Rebecca Evans of the Consumers' Association legal department says: "I would say they were legally required to return cash when the car was returned intact. But it is difficult to say what the customers could do about it. They couldn't start charging interest per day unless it was agreed in advance. It is pretty dodgy trading practice, which they should refer to their trading standards office. If it caused financial problems, for example by making them go overdrawn, they might be able to ask for recompense. The law says you can claim for what is directly and forseeably lost. The company should have warned of this in advance."
Many hire car companies take a deposit by asking customers to sign an uncompleted credit card payment form, but Ms Evans warns this too may cause problems if there is a dispute over the state of a returned vehicle.
The Consumers' Association is currently involved in legal action against Hertz over a separate dispute. A Hertz customer hired a car at Marseilles airport at a special discount rate. He says he was not advised that under this low-price scheme he waived insurance against theft - Hertz says he was advised.
The car was subsequently stolen, and the customer is refusing to pay the value of the car. Ms Evans advised: "Read the small print of a hire car contract, check the insurance position."