Pravin Limbachia was one of a number of retailers who called about the 'Whodunnit in Doncaster' tale, where a 'customer' pretended to be talking on his mobile and then attempted to photograph a phone voucher he had no intention of buying. Get the money first is the simple message.

The most interesting variation came from Martin Drinkwater, who runs Crowhurst's in Tonbridge, Kent. His experience featured a bloke with a broad Southern Irish accent. "The deliberate confusion is caused by the person requesting a '3' Mobile top-up voucher, which sounds like T-Mobile. When you confirm 3 Mobile, take the money, process the voucher, the response is 'I asked for T-Mobile not 3 Mobile' but an attempt was still made to transfer the info to the phone, in my case unsuccessfully," concludes Martin.