It was gift to us from the previous tenants! The name is I'm guessing the name of the previous tenant who left it for us. I've asked our agent to see if he can contact them to get details of when they cancelled the account etc, but I don't know if he'll have their forwarding details as they returned to the US. PCCW say they need the name of the old account / account number to see if the account is still active, they can't search by address.
Nightmare! I don't think trying another provider will be any good though, if the line is in use?