If those are your worst stories, you are lucky so far. My wife and I literally keep a Google doc with all of our customer stories, it's fun for a laugh now and again. Many don't understand the importance of keeping those customers happy, but they are the first to run out and leave bad reviews about your company. And, from my experience, reviews drive business almost as much as anything else these days.

My advice would be to create and set aside a monthly budget for this sort of thing, so it is easier to "let it go" and not take it personally (that's the hard part for me).