Crediting a customer

[Nigel Titley]

I've got a customer who has overpaid. His cheque has been credited and 
reconciled. I now need to make a credit back to his account and write 
him a cheque. I can't think of a way of doing it. I've tried making a 
negative payment to his account but this isn't allowed, and I've tried 
raising a negative invoice and neither is this.

Any thoughts on how I can do this?

Thanks

Nigel