Both eBay's and paypal's guarantees work only on goods which were faulty on delivery or more if the fault was not discovered at that time. Something that stops working [etc] after a period of time is not covered I'm afraid.
If the retailer is a business then they may offer a guarantee or you may have legal rights that you can utilse though - to be honest - it is more difficult when buying on-line and might not be worth it
@ipanchal
