I have an employee here that signed up for a free DropBox account with their work email. The account has been compromised and the MFA phone number has been changed, so even though I can get a password reset email, I can't complete the change without the MFA code. The account has sent out numerous phishing e-mails to customers and vendors and is continuing to do so since they have hijacked the account.
Is there any way we can disable or shutdown the account? We own the email address and domain. It's sending malicious content to our Customers, at the very least I need to disable them from sending out sharing emails.