Ive been threw this a few times with a few people. To stay impartial Id suggest posting all communications between you two. Not to sound rude but it does seem one sided since the seller is either unaware of this thread (very unlikely) or he is horribly guilty.
People always get heated with issues like this when its one sided. So yeah post every thing up and it shows every one how you both handled the situation and lets them judge for themselves.
Just some friendly advice. Hope it all works out for you.