Did you make any attempt to post on the forum about losing the account? I still don't understand what you thought happened to the account, getting your email address deleted does not mean you lose access to your account as long as you still have the password. If you know the email address, did your password stop working and when?
If you know the secret question of the account you can get it locked to reduce damages till you regain access.
I'm guessing his password was reset along with the email address. Thus, the account is no longer associated with the original credential the OP has. This account was probably hacked and sold when the OP was inactive and is now being taken advantage from someone who's incompetent to create their own account and meet the necessary requirements for ranking up.
The OP should be cleared provided that he's able to sign a message from the addresses still found on the spreadsheets of the campaigns he participated years ago. That should be enough evidence. Good luck!