I purchased a pair of Sony XM4 headphones advertised as brand new on eBay, but upon opening the package, I received used and damaged headphones that won't even turn on. The earcup was detached, there were no accessories, and they had pet hair and a strong odor. When I confronted the seller and asked for a full refund, he accused me of trying to defraud him and threatened to file a police report and have my eBay account shut down after I returned the item and left a negative review.