you only seem to reply to the ones that give you hope. you need to realise that you have quite a high chance of losing the cash so dont get your hopes up. I think next time you should try western union or something
payments can only be held for 180 days before they're automatically refunded to the buyer.
that is if the seller doesn't act on the dispute within the 180 days allowing paypal to make a decision before then.
Chances are you won't win the dispute.
Your best option would be to add screenshots of the trade, however if you didn't take any screenshots then you would be better off ringing them up and explaining the trade.