Balls to you all lol. Should have seen it coming right? Think I have his number, I'll give him a text and let you know how it unfolds. Maybe he didn't know it was screwed but to not even check it before posting is pure negligence
Realistically it's second hand. You don't get a warranty but you didn't pay for it either.
Legally you have no comeback, morally it's up to his conscience. Plus, if he doesn't sort it he will find it incredibly difficult to buy or sell again on any UK forum