I thought the customer was always right anyway. It is hard to please customer management and keep your sanity at the same time. Another reason to be wrong because the employee will strain to make it right even when its wrong. why is it so hard to please some of the customers all the time and all of customers some of the time time and none of the customers none of the time!
This whole thing is stressful, people are just people, just like you and I. Some are honest, some are morons out to get everything they can for nothing. My advise to you is: follow the rules down to the wire. If your customer is still not satisfied, don't take it upon yourself to be intimidated by some idiot moron and go against the "rules". They don't care if you loose your job or not. Call your manager to settle things, they get paid the "big bucks" we don't. Use your gut feeling, if something isn't right, explain to the customer that you would be happy to call a manager to assist them because you only have authorization to a certain point. When the manager arrives, and more than likely they will "make it right for the customer", thank your manager for helping, then thank the customer for waiting. Over the years I have found that this takes the stress off of the workers, and puts the "blame" onto management, if need be. You have followed the rules, your backside is safe.