ICloud removal

My problem is removing an iCloud account from an iPad. The login for the account is an email address which we can no longer access, and it has never been verified on the iPad. I have tried to remove the account, but it doesn’t accept the password.

The iPad has been updated and I have changed the login email on the iTunes account, but when the iPad was restored it placed the same original account on the iCloud section, so whenever I back it up and restore it