if he doesn't get back to you report it to ebay,
they always side with the buyer, you should get a full refund thru paypal,
its a bit of messing around and takes time but you get it eventualy,
only thing going against you is why it took so long to complain,
the seller will prob say it was fine when he sent it and you prob put it
on you car and damaged it, now your trying to claim it back,
but just stand your ground,
the best way is prob to offer to sent it back to the seller for a full refund if he claims its ok, (unfortunately at your expence but best out for post than £330),
just try to be reasonable with him to see what kind of reaction you get,
if he starts coming the cunt just get onto ebay and paypal and try take him to the cleaners