If that's the case and he was unaware of the damage (possible I guess) I would say that a goodwill gesture of like £20 refund or something would be the best I'd expect... Certainly worth getting in touch with him and see what he says about it though. With regards the front lever I can't see the crack you mean, looks more like marks from where the snapped part of the clamp has rubbed at some point or the damage caused when the clamp actually snapped when it came into sharp contact with something like a brick wall! However, I'm sure you know what you're talking about Matt so I'll take your word that's it's unusable.