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OP you were not hacked, you gave out your account details and lost it in a failed deal - You can proceed to account recovery and provide the necessary information to get your account unlocked. That was a dumb move.
I think it would be a bad idea for admins to hand this account back to the previous owner, who voluntarily handed it over to someone else. There was no hack. There may have been some sort of a sketchy deal, or the OP might be lying, they might have been paid (monetarily or otherwise) for all we know. Only a proper escrow could possibly untangle this mess but it's too late for that.
It sounds like "infinity money glitch".