I worked in Gamestation for a year between College and University. I accidentally printed off a £1,000,000 Credit Note for a guy once when he was trading in his console. The touch screen was out of alignment and I was a nooby, ended up hitting the 00 instead of the 7 once, and the 0 twice. Or something like that. I can be a bit of a clutz with touch screen tills.
Needless to say we didn't give him the note, and wrote it off instead.