Hi, I sold a Samsung Galaxy Note 10.1 on ebay for $186 I received the money on the 10th of August I shipped the tablet before that on the same day I recorded a video showing the tablet working perfectly...the buyer received the tablet on the 17 and on the 19 I received a return request the buyer said the tablet wasn't working even tho I ship it working perfectly....now I'm worried that I have to accept the return and refund the full money....of course the buyer not going to say he broke it...so I lost about $220 dollars for shipping and a tablet worth nothing really? What should I do?