I assume this is the auction.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3239891526

File a fraud report with Ebay and paypal if you paid by paypal.

Absolutely you should leave negative feedback. Something calm and factual.

such as.

Seller misrepresented condition refuses to refund.

So what if he leaves negative feedback? What is he going to say? Most people will see that it was retaliatory and you can leave a follow comment to it.