Broken window. Stereo out and back in wrong. Bad unit. Reading between the lines it sounds to me like your car was broken into on thier lot, and the head unit was stolen. You might even have a bad unit that was laying around from an earlier removal. Bad beat all around.

Incidentally, I sometimes sit as the judicial officer on small claims matters. When things like this come before some of us with the service company tryiing to hide the ball on the consumer, we can go through the roof and even assure that you are made whole for all the trouble as well as the financial loss.