I don't think Accuquilt has a responsibility to keep your purchasing records, but that being said, I've always had good interactions with them. I don't see why they wouldn't accept a return on a standard item. If it was not sent in error, they don't have an obligation to offer return shipping, but most places will do so if you explain and ask for an exchange for a different die that you don't have instead. I'm pretty sure that unless you are a shop you will not need a second die. These things are pretty sturdy. Just my HO.