"Serious problem" prevents broadband activation

The other day I was helping to install a BT Home Hub on a line that had just been activated for broadband - supposedly. But the broadband light on the hub remained resolutely off so I called BT Broadband Tech Support. The first person I talked to confirmed that the line had been activated and put me on to the next level of tech support. The second guy had me switching filters although I had already tried all that. After a while he ran a line test and told me everything was fine. About half an hour into the call he suddenly had a piece of inspiration, asked me again what I had told him at the outset, that this was a new installation that had never worked, consulted the records and discovered that there had been a "serious problem" at the exchange and that broadband had never, in fact, been activated.

This leaves me wondering what sort of problem this might be? We have to wait several weeks until BT say they will have the problem sorted. And what do these guys think they are doing when they run a line test if it can get a positive result on a non-existent connection?

If you tell us the name of the exchange then someone will have a look on the Openreach Red list.

I have no idea what the Openreach Red List is, but the exchange is the one in Sawston, Cambridgeshire.

Can't see any problems listed anywhere for Sawston. Must be a very local issue. Hopefully it is not because your line is too long.