You did the right thing.
You have been beyond patient and waited a LOT longer then most people would have. You have been a lot NICER then most people would have.
You have done absolutely nothing wrong. Not during the transaction, not here, not by finally posting.
Let the chips fall as they may now, but I honestly think you have a BIGGER chance of a refund now, then you did before. The more he thought he could bully you and hold you off with BS excuses, the more he was going to do it...
If nothing else, by standing up for yourself you will feel better about yourself, and just think...you may have saved quite a few other people the same headache you had to go through.