I bought a Buy it Now item, paid, and realized it was the wrong shipping address. I can only use the one I paid with for UPS, and not USPS. So I asked them to send to my PO Box, and now they say they can't. I don't know what to do to correct this. I'm getting upset because it was a SUPER amazing deal, but I almost feel like the seller knows this and regrets selling it to me. I already paid, what should I do to resolve this?