Buyer claims there is something wrong with items he has received, and demands partial or full refund. If not able to get refund (with items kept as well), leaves negative feedbacks. Does it routinely, which is obvious from his eBay page. If you have had problems with this buyer, please don't forget to report him to eBay, even if you decided (understandably) to refund in order to avoid the negative feedback. ONLY MULTIPLE REPORTS FROM DIFFERENT SELLERS may force eBay to recognize buyer's pattern of abuse and take action against him.