What would be the proper process? Start a scam accusation thread? I know quicksellers has a few accounts so I will list them all for us to zap with negative rep.
The issue is that this account has been tainted with negative rep and it was revealed by Quickseller to the public that this account has been purchased (breaching the agreement). Furthermore, if bayuo is telling the truth (although I doubt he is), Quickseller further breached the agreement by telling me this was not a hacked account. He assured me that it would be problem-free.
I think you should ask for a refund by threatening the account seller that you will publish his to-be-sold accounts and they could be worth nothing then.
Other than that, I don't see how you could have pushed him to pay you back...