Facebook complaint: Being ripped off by FB marketplace

Ok so bout two and a half months ago I was selling stuff on Facebook marketplace cause needing funding for Christmas gifts, and so I decided to make my postslistings for not just local but broaden it’s availability further so put it for shipping as well in which Facebook gets percentage for selling through them middle manning it they give you shipping label so on so forth so sold one of my alpine stereos to buyer in different state they paid and so I was supposed to receive payment within 20 days after buyer receive or something like that .Here’s the thing I kept in touch with the buyer and checked the status of transaction daily up to days ,weeks, and now months after buyer received not just that I talked to buyer he said he paid Facebook sent me screenshot of his transcript showing he paid Facebook specificaly for it than he left positive review saying he loved the item no complaints. So when I look at this transaction for past 2 and a half almost 3 months now it’s says pending payment..wtf why in the fuck won’t they give me my money I set up a checking account with my profile for it and everything….so once again wtf?