Things happen at the same time that time. After dealing with that customer, the phone started to get crazy and two customers are in line waiting to get their transaction done.
The story about the complain is not complicated. The customer just wanted to make me feel bad about what happened to her gift card and the merchandise that she cannot purchase with it. Oh well, I will wait for her to call on Monday. She is very welcome to talk to my manager anytime.
You cannot please everybody. And that is true. Though you gave your best customer service, still, some people do not appreciate you.