eBay's money back guarantee only lasts for 30 days. After that, they have no further involvement. Sellers or manufacturers' warranties have nothing to do with eBay.
You can try taking up your warranty claim with whoever issued it. Unfortunately, warranties often prove worthless on eBay. Sellers can claim warranties, but we know from the number of times this is asked that when things go wrong many don't want to know. Warranties from overseas sellers are best assumed to be meaningless and unenforceable. Even manufacturers' warranties are liable to be invalid for items bought on eBay; not many sellers here are authorised distributors, and items may be clearance stock, seconds, customer returns, grey imports or just plain counterfeit.
Buying from unknown sellers on eBay is not like the shops. eBay warned you in the user agreement that "they do not guarantee the existence, quality, safety or legality of items advertised, or the truth or accuracy of descriptions". eBay is a jungle.
