Toxic buyers make me want to quit eBay

Sold a collectable statue back in January, buyer paid, I shipped, and I thought everything was cool. Then about 2 weeks after it was delivered buyer opens a claim to return stating it was "not as described." Claimed a "mold smell" and a dented box. Ok fine, I'm not going argue. I accepted the return, buyer sent it back, issued a refund, done. I thoroughly inspect the statue to investigate the buyer's claims and surprise, find nothing wrong. Ok, wait a couple weeks and resist it. Sold again package it up and ship it out, delivered no problem. Lo and behold the same buyer bought it the second time around. I didn't realize it until he opens another return claiming the exact same thing. WTF?!? I know there is nothing wrong with it because it was inspected multiple times by multiple people including myself. So what the hell is this guys goal here other than to mess with my listing's and ruin my reputation with eBay. He's a reseller so it's feasible that he's trying to eliminate competition.