Jay's answer is right on the button. Let me add a couple of things.
Picture yourself working at the Sears tool department. You are innocently trying to keep the signature measuring tapes stocked up on the shelves when you are accosted by a gentleman who demands you replace several handtools. He has an attitude of expectation, he's angry, and treats you like you aren't worth the $7 an hour sears is paying you to take his abuse.
An hour later, after you told the guy where to go, another guy walks in with a belt sander and a couple of screw drivers. He treats you with respect, has a smile on his face, etc. You know he will be happy no matter what the outcome by his behavior. After a pleasant chat and a little research, you send him on his way with a new sander and screwdrivers.
My point is, when you go into any store with a beef about a product, start with the honey. If you don't get what you want, try some honey a little higher up the chain of command. Be appreciative. Be nice. Be polite, and respectful. You will get a lot farther by making people want to help you instead of making them want to throw you out on your head.
Okay, enough of the soap box.
As far as receipts, sears keeps all credit transactions on file for something like 5 or 6 years, and can usually pull them up right at the register. If the person who gave you the sander used their sears card, the receipt is in the system. Even still, if the sander is a craftsman, you shouldn't have a problem returning it, or if nothing else, gee, does it just need to be serviced?