Be happy you got your money back, there must be another one you can purchase. Life is too short way to short to get upset about a coin...it's a hobby relax enjoy
When we choose to bid on a site, we choose to accept their rules. When we travel to a place, we agree to abide by their laws. There are places in my own country I won't go. The number of places I won't buy coins increases. I may run out of places someday.
First off, you're not going to get the coin, no matter what you do. Having said that, you need to ask yourself if this guy pissed you off enough to spend your time and effort on the phone with eBay with the best possible outcome being a demerit on his account. Realize also that this is the account of some guy you're not going to deal with again anyway. In short, you got your money back. Forget about it and move on.