How do I fix "This Apple Account is not active" error?

I see this question has been asked numerous times, however I can't seem to find an answer.

I recently created a new Apple account and logged into this account on my Iphone. The next day I was logged out of IMessage/ICloud and prompted to log back in, however when attempting to log in I now get the error message 'This Apple Account is not active'... I then went to reset password and received an email in response to state that my request was denied.

I've called Apple Support and ran them through the issue and they are seemingly unable to help as, 'for privicy reasons' they cannot tell me why the account was moved to inactive. This account is new so I know there's no breach of the terms of service.

Now my phone is linked to this 'inactive' account which I can't log out of, and have no way to logging in to use it.

Is anyone aware of a fix for this? Either to force a logout on the device, or preferably to regain access to my account via an appeal?

Thanks,

[Re-Titled by Moderator]