Refunding a customer

I am trying to process a customer return. It is a refund of a deposit for a cancelled service. I have MYOB invoiceing set up for services, not items because I don't sell items and every service is different with different amounts. When I try to do a customer return it only lists items. How can I make the customer returns for services so I can easily enter the amount of the service without having to make a new item every time? Thanks.