When I worked at a supermarket I served on the customer service department which dealt with complaints and refunds. Some people would complain about anything and the same people often demanded refunds. There was one guy who used to go through his cupboards from time to time, find all own brand out of date tins and packets and bring them back for a refund. We were obliged to give him his money and he would walk off with a tidy amount in his pocket. I would have felt very uncomfortable about this but the store gave him the money back for goodwill. Would you be brave enough to do this?