I would like to report a seller who is refusing to refund me for a returned item which...

I would like to report a seller who is refusing to refund me for a returned item which he is disputing has not returned back to the warehouse. I returned * items to the same warehouse from * different sellers. The other seller refunded me for the return so it’s hard to believe how the other same item to the exact same warehouse was not returned. I have proof of return. Receipt with tracking number for all items returned to the same warehouse. **The seller (syst*gz) wouldn’t reply back to my messages so I opened a case and asked eBay to step in. He then was quick to reply and asked me to close the case and he will refund. So I did. I was tricked into doing this and he refused to refund again saying item hasn’t been located so will not refund. I can send you copies of proof of return and the messages from the seller. **I really hope someone can help me resolve this issue and get me back my refund. I am unable to re open case again.