It may not always be the smoothest process, but I don't think they're trying to screw us.
I for one did just about everything I possibily could do wrong when I sent in the UPCs. I peeled off the one from the Nano, and the one from the iMac I only cut out the UPC itself, without the serial nbr, etc, *and* I then pealed away most of the cardboard backing--all of these are things that the instructions say not to do...I really should pay more attention to these things.
When I realized that I'd done all of these things wrong I called customer service and the girl there said that we should just wait and they'd let me know if anything was wrong. From what she said, it sounded like the itemized receipt from the store was the most important part (and I had included that). I kept a close eye on it from the website, and today my check for $199 arrived without any problems at all.
Surely if they wanted to screw everybody and take advantage of the situation I would have been pretty high on the list after all the rules I broke.
Just my thoughts.