Cannot sign a contract: Adobe says: "Your account has been deactivated"

I recieved an e-mail from the customer in december.

Until today I was not able to sign it with adobe sign, becaus I always get the message:
"Can't log in to Adobe Sign. "It says Your account has been deactivated. Please contact your support staff."

There is no Call2Action like

- sign without login

- re-activate account

- sign in with a different account

How can I sign the document?