Try contacting the user, but there are no promises he will answer or even give an account to you. The user is being banned for recently openly admitting to scam quitting and will not be allowed back unless they pay the people they have scammed, including your full amount.
Hopefully this encourages you to either user a middle man, not paying a full amount until something is done, or even making sure the user is trusted.
I'm sorry for your loss. Hopefully he will contact you and give you the account. I'm not sure if it is too late to dispute the payment or not, most likely is, but since he openly admitted in scam quitting, I would go ahead and try that. UNLESS HE IS GIVING YOU AN ACCOUNT THAT YOU PURCHASED, OR A REPLACEMENT ACCOUNT.
Also, please note how important it is to start a report soon after something has happened. This case should have been made LONG before now. It should have been first brought up in 2014, not two years later. You're lucky the user recently openly admitted to scam quitting and got banned, or else this case probably would have not gone through and no actions would have been taken to the user. So PLEASE PLEASE PLEASE try to open a dispute right when you think things are getting fishy.
Please let me know if there is anything I can do to further assist you.
Thanks,
ProjectPact