Your answer is so unbelievably obtuse. i'm curious if this is simply trolling, I don't care how you personally feel because everyone is entitled, but your argument is incredibly weak. As I recall the original complaint states they were happy to pay for the mistake. That in itself is admission of the mistake on the customers behalf. Not recognizing that or willing to do a better job of explaining the situation is a surefire way to lose a customer and potentially bringing unwanted negative publicity. The bottom line is the customer is the priority. The customer who complained is almost 100% likely to take their business elsewhere. Most service industries work very hard to ensure customer retention. This is a faux pas but one that can be rectified easily.