Since eBay requires you to respond to his emails can you merely write "thank you for your most recent communication" or "received" in response? He's enjoying this in some bizarre, perverse way and every time you attempt to reason with him he just gets more and more obscure and twisted in his claims and accusations.
I'm also impressed with the clarity of your explanations and the way you've managed to remain polite in the face of his refusal to be intelligent and his passive-aggressive attitude. He's trying to get to you and he's becoming frustrated that you're not taking the bait.
I'm also impressed with the clarity of your explanations and the way you've managed to remain polite in the face of his refusal to be intelligent and his passive-aggressive attitude. He's trying to get to you and he's becoming frustrated that you're not taking the bait.