the whole NAFTA deal almost never pans out. for it to work the stores have to declare it properly, so when it his canada it goes through properly, instead they put it in a box, slap on the address and send it. once you get the package, i don't think theres a way to backtrack and claim it was made in USA and get the money back
You can dispute the charge, but it's a hassle and it takes forever for a ruling. Probably not worth the time unless you get hit with a pretty big duty charge on a NAFTA good.