Why is it impossible to email customer support?

Summary: A participant raised a concern about the challenges of contacting customer support via email. krazzykats and kensgiftshop responded to the initial discussion, but none of the participants provided further content or solutions to the issue mentioned.

I have a seller that purchased from me twice and wanted their order sent immediately and I was able to. Almost a month later the buyer contacted me and opened 1 case and sent an item that wasn’t what I sold him. Shortly after getting that refund he opened another case and did the same exact thing. Each time he ignored me when I asked what the issue was. He opened the case saying “broken” and I would offer a partial refund. Each time he wouldn’t respond to the partial refund until the case time limit ran out then he would have eBay step in to force me to accept a return. I would have accepted a return if he had denied the partial refund but I think that was part of the plan. Once he had eBay remove me from the process eBay closed the case in his favor and the different items were sent back. After being delivered eBay makes it impossible to appeal. In both returns eBay said I can open an appeal and both times when trying to start an appeal it says the case has already been closed preventing me from opening an appeal. I reported the buyer twice showing that the item images he sent were different then the item I sold him. Each time nothing has been done. This second return is way worse than the 1st one. He sent me a scanner that someone engraved with numbers and letters on all sides and he took the new battery I sent him ($50 on its own) and sent me back a dead old battery. I also mark my scanners and batteries with a dot that isn’t on the scanners I was sent back. This has cost me $300 plus shipping there and back. I think it’s crazy that this is allowed to happen. I read that I should post here to see what support might have to say here. The most recent case I’d is 5379803400 and in that case support should be able to see that the image he sent is not of the same item I show in the listing.