OP, please post some proof that you sold him the account and I'll tag it.
As others have said, account selling is not against the rules but it is generally very much frowned upon, and I tag account buyers & sellers when I find them. It's a bad thing for the forum overall, and as you can see yourself account buyers are pretty shady (in general).
you can report him for account selling to trusted members of this forum, I'm sure he will get red tagged and he will be disabled from Yobit I read in Yobit that you cannot join the campaign if you are red tagged
Yeah, but there needs to be evidence of the account being offered for sale and transfer of ownership. I don't doubt OP's story, but I want to see proof before doing any tagging.