In my recent experience (twice) with an incorrect product being supplied (due to erroneous description by seller), eBay has immediately intervened and responded to my report by offering me a refund, rather than contacting the seller and (in my case) asking for a product exchange - which I then had to do direct with the seller. (In both my transactions, the seller could not supply the 'correct' item, so a refund followed by re-sourcing was the only option, but I got there eventually, if a little poorer.
It does seem from the seller's silence here that he might have ceased trading, in which case the goods may or may not be in existence, and possibly still retrievable, subject to insolvency procedures if applicable. But if he is simply not resoponding, for whatever reason, eBay may be able to throw some light on it.