S: Account got hacked and every time the account is closed down, hacker keeps on re-activating it. How to know if account is fully closed?

my other email account has been hacked and everytime I close it down the hacker re-opens it and personal and sensitive informmation has been circulated I'm now at risk of losing my position. I've paid a security company to close the account down but I need to know that it's worked

Original Title: my email account has been hacked and everytime I close it down the hacker re-opens it