My neighbour has the same problem - it is fault in the external box in the nearby street - I know this since it has happened several times to me. We need an engineer to go to the external box (not make 2 visits to our respective flats) and fix the problem - asap - not next Tuesday/Wednesday which were the earlier appointments we could book.
Thanks for taking the time to let us know about this, I've been able to locate your account to run some tests on the line as well as check for issues in your area.
There are no open issues in your area at the moment and so with ensuring we're getting this issue resolved as soon as possible, we'd like to arrange for a member of the team to come and take a closer look internally and externally.
With that in mind, I'm glad to see the appointment has already been arranged and I'd love to hear how it goes.