This happened a long, long time ago. I saved up $250 to upgrade my CPU, and took it to the counter. I was bs'ing with the clerk about something or other, wrote out a check, he bagged the chip, and I left. A few weeks after enjoying my rocking new 150Mhz CPU (yes, indeed), I noticed that the check wasn't cashed. I opened my checkbook, and was greeted by the check I had written for the CPU and never even took out of the book.
I wouldn't' do this today, but at the time I was like "pshhhh! Sucks to be them!"