3rd party Amazon seller sends package to wrong address. Advice?
Right after Christmas I purchased a few books from a third party Amazon seller. Nothing too expensive -- $25 after shipping -- but costly enough to make their loss rather annoying. They were due to be delivered last Monday (a week prior to this post). But I never found the package even though the USPS tracking system said it had been delivered. They deliver behind a locked door so theft seemed unlikely.
I waited a few days to see if the package would show up; when it did not I called USPS. They told me that the address the books had been shipped to does not match the address Amazon has on file, although they wouldn't tell me what the difference was (understandably).
On the other hand, the seller tells me that she has a receipt from USPS with my correct address. She says she's looking into it.
So I'm not sure what to do here. I could probably file a claim with Amazon and get a refund, but I'd hate to do that when it's not the seller's fault. I could wait it out but I strongly suspect that I won't ever see the books I ordered. And if it's her fault then, as far as I can tell, she has no incentive beyond ethical reasons not to lie and put the blame on USPS. Any advice?