In my years of running a car wash, the best car wash refund policy is to refund money when requested. Even though you may have the rare customer who claims to have put $10 worth of quarters in a bay that isn’t working, most requests are going to be legit (and if they aren’t is a few dollars worth fighting over?). Also refunds can be a way to build lifetime loyal customers. Although there are a few that will try to abuse this type of refund policy, most of the folks taking the time to report a problem are legitimate. By quickly responding and giving them more than their money back, they are very appreciative and become a very solid customer. When you consider the volume of revenue, typically isn’t worth the worry to fight giving most refunds. Refund requests will also be more legitimate if you are using tokens versus coins. By refunding tokens, your potential loss is lower (tokens cost less than coins) and there isn’t much to gain if they are scamming.
Track every name, address and phone number of people calling for money lost in the changer to keep tabs on repeats. Almost every time it will probably be verified by the changer count.
Cameras can help solve most of the refund requests too. By verifying lost money by equating the time customer said they were there, to the problem they are reporting. Some operators will verify every single refund request, even those for less than one dollar which seems like a huge waste of time for the operator. How much did it cost in the operator’s time to track and deny a $1 request?