Looks like something has gone wrong with the circuit build.
You normally get that page when you're connected with an incorrect login. As your using a home hub, the username in that can't be incorrect, so the radius server must be configured for a different username suffix.
or, unlikely though, it has somehow generated a task for an engineer to switch the port in cabinet (not normal procedure) and as such, you're now connected to a port which doesn't have the correct routing to the radius server, or has been configured incorrectly.
This likely needs moderator intervention.
That's the landing page when you are connected to a BT Broadband connection but don't have a BT account. You need to go back to customer services. Its not a technical problem with your line, its an account problem.