Skype stole some of my money a couple of years back - using their unused credit scam. I have a very simplistic view on honesty and integrity. I have always tried to be honest in all my dealings and I expect others to behave in a similar manner. I have never traded with Skype since their theft. I have also actively advised others to avoid them like the plague.
I, too, lost skype credit several years ago, but it was my own fault. After repeated warnings, I failed to take action. The fault was mine entirely.