Unable to register on new mac. Keep being told key is associated with a different account

I've been trying to activate parallels on my new mac, but whenever I try I receive the message "
This license key is associated with another Parallels account. Please sign in using this account and try again."
I made sure all the info was right and tried logging out and back in again, but I still keep receiving the same error

 

Hello, we have sent you a private message. Please help us with your license key over there.