Phone Line

[Robblacky]

Moving into a new flat and im wantng to switch my BT broadband from my old address to the new one.
The new flat has a BT phone box inside the flat and a dialling tone, but when i spoke to BT they said that address doesnt have a BT line connected.
They told me to dial 10707 from the phone and see what the phone number used to be and they would check to see if it was one of theirs, and again they had no record.
So my question is how do i find out who the suppier of the line is?

[craft1948]

Cannot the previous tenant/landlord help? I had this problem when transferring my broadband as the previous tenant was with Virgin cable.