Oddly we can get internet (though it does crash out a fair bit at times) but no dialtone, just crackles.
BT seem fairly certain that the fault with our line is down to 'their' equipment (though they still have to come into our flat to try to correct it.
But if it's 'our' equipment they'll apparently charge us something like £116 call out fee plus £99 for each hour or part hour. That might be +VAT and it might have been £99 for each half-hour or part thereof.
This is really quite scary. Bless Thatcher for privatisation, eh? :-/