That makes no sense

Friday I popped out to get the salmon and cucumber sandwitch I had been craving for three days (and yes it was delicious) and a customer came in and paid a fellow co. worker by cheque whilst I was out. On my return my fellow co. worker "idiot?" queeried the cheque with me. They said "The document number is right, the amount is right, but the name on the cheque is not the customers" I can think of many reasons why this could be so. But this was obvious it was a counter cheque from the building society. what can you do when you work with IDIOTS!! to add insult to injury this particular fellow co. worker always reminds me they used to work in a bank.