Item returned to seller, UPS was unable to deliver it. Seller says they will not issue a refund? What to do?

I ordered something and for whatever reason, UPS returned my item to the sender/seller with the UPS tracking indicating “not listed on building directory” when they allegedly tried to deliver the package. I don’t live in a building, it’s a regular house so idk what that was about and I double checked my address on my original eBay order and it was correct.
Anyway, UPS sends it back to the sender, and the tracking link shows it was returned back where it started.
The seller when I contacted them, advised they do not issue refunds when a product is returned to seller “as there are fees we incur, so we are unable to offer any refund” they also will not be reshaping the product to me.
So they have my item back I paid for? What do I do?
I tried to go to the purchase to have Ebay step in to help, but that option does not show. Who do I contact for my money back?