Well, I was going to write up a piece on Ryan Carson of DropSend and his poor example of customer service and great example of what not to do, but Patrick already beat me to it. So just go read his post to see what I would have done.

http://microisvjournal.wordpress.com/2007/02/16/how-to-deal-with-abusive-customers/

Not to be too egotistically, but I think Patrick is the new me :-). Since I haven't had as much time to write lately I'm really glad he's picking up my slack!