Here's a great article on Gamasutra about customer support:
Customer Support Orientation Guide
Sadly I get the kind of emails described in this every day.
“XXXXXXXX.com your CROOKS. The Soliaire Games Are RIGGED. A deck of cards does not have 6 5's or 7 Queens. Their is no way mathematically that after your hand is dealt that you go through the whole deck and not have one move, not just one game but 12 games in a row. Cards change and they disappear. Your CROOKS, and a bunch of cheats. I wouldn't buy your games for nothing.”
This is really common. People email who are certain that the cards are not random. As if two of the same card (when there are more than 1 deck) can't ever be next to each other at random. I get emails are cards being missing (usually this is in games where the cards are buried in the stock, when it deals 3 at a time). And then there are the really fun ones who think that I have deliberately programmed the game to be hard, not for everybody mind you, but just to screw with them personally.
Ah, the joys of email customer support.