Fake tracking number scam on eBay?

I ordered an item on eBay for $535. I used Klarna to purchase the item. The tracking information seemed normal and I got a notification today that it was forwarded.

I went to the post office and they gave me the package with this tracking number, except the package had a different name and apartment number. The person moved and so it was marked vacant. The post office said this is a common scam called a “fake tracking number” scam. They gave it to me without checking my ID first so they marked it as “picked up.” The issue is, this package didn’t have the item I ordered in it as it was too flat, didn’t have my name or apartment number and is now showing as picked up.

The seller says there is nothing I can do and the post office wouldn’t let me take a photo of it due to their privacy policy. Apparently eBay won’t refund you since it shows as delivered/picked up.

What is my best option to get a refund? I have no package, I will have to start paying Klarna soon, and the seller blocked my Facebook account (where we agreed to do the deal on eBay) and responded to my eBay message saying they couldn’t do anything.
Am I SOL and stuck paying for an item I don’t have? I should have known better when they didn’t have any reviews at all.