No point now, Craft. I was trying to reunite a little lost dog with its owner. The telephone number was on it's collar but the number was permanently engaged. BT were incredibly unhelpful.
I would have taken the dog to the vet the next morning to see if he was chipped - but after trying to contact his owner for a couple of hours, I ended up ringing people I know in the area the dog was found, and happily he's reunited with his owner now - no thanks to BT. I just question why they now need an address to check a fault on a line.