I got the message I'm on a BT light user scheme
You cannot make use of 1899 if you are on a BT light user scheme. You will have to contact BT to cancel your light user scheme. Even if you have already cancelled your light user scheme with BT but you still get the message you are on a light user scheme, you will have to press BT to reset your line. BT often refers these problems back to us but these calls do not even reach our network so there really is nothing we can do to fix this. Unfortunately you will have to keep going at BT yourself insisting they fix the problem for you!