4 steps to make an unhappy client happy
Putting things right
Every photographer will end up with an upset client at some point. The notion of "dealing with" that situation is the first attitude you'll need to let go. "Dealing with" something is a quick fix to make it go away, but that means your client is likely to disappear as well. When something goes wrong, you want to repair your relationship. Rather than getting defensive or making excuses, be prepared to empathize with your client and help both of you come away feeling better.
Source: Psychology Today