John D Drumheller

I am an amateur coin collector, only United States editions. I purchase from time to time at on line auctions or eBay. I have a question. I purchased a 1914 Buffalo Nickel at an eBay auction site (THE BOSTON COIN) that was advertised as a "monster" nickel from a 1973 collection. Seller Notes: "INCREDIBLE". It was listed as uncirculated and there were adequate pictures of the coin. I won the auction at $565 and later received the coin. I immediately took it to a local dealer to have him send it for grading. His immediate reaction to the coin was that it had been artificially toned but he would send it in anyway. After an eternity NGC returned the graded nickel as "UNC DETAILS ARTIFICIAL TONING". I texted the seller and they immediately got on the defensive and seemed to rely on their "No Returns" policy. I couldn't get anywhere with them. I told them that i wanted to return the nickel and that I would take other merchandise on their site in return rather than cash, and would also expect them to charge me a restocking fee. They have now "ghosted" me and I am unsure what to do. Looking for advice. Thank you, John