The right thing is always the right thing.

No matter what you do, do the right thing. If that means going the extra mile to make a customer happy, or not cutting corners, doing the right thing will lead to good qualities that you can grow upon. One customer lost is one to many. For example, if you ship an item and the customer isn’t happy and wants a refund, give them a reason to come back to you. I had a bobblehead I shipped out a few weeks ago that arrived broken(mail carrier) and the customer wanted to send it back for a refund. They shipped it back, I issued a refund and then I shipped another one on me. They ended up paying nothing for it. A week later the same customer bought another bobblehead and was satisfied and I know they will be a returning customer. 

Always do the right thing if when you know you might be not at fault.