My advice?

1) Tell him that the item was damaged internally, ect ect. and that you want a refund immediately, and that if he doesn't within 36 hours, you will be filing a claim with PayPal, which locks his bank account until resolved.

2) If he refuses, file your claim immediately as a misrepresented item. At the same time, file with eBay. Normally this does nothing since most of the time it's from their PowerSellers (who they hold very close and never take action against), but since he isn't one, they will make sure it's taken care of.