I also think something strange is going on. What it is I dont know but a 5 day outage and nothing on any of the status checkers. If it was either the copper or Fibre MU.. or even the cab, I would expect something to show up on the Zen status.
I then started wondering if MU could be something to do with the Sky backhaul but then again you'd expect them to put something up on their own SS. If they had to dig up the road, then would there be anything on roadworks.org as surely it would cause some traffic problems.
If it was a new pair - or rather pair swap- then I wouldn't expect you to then have to wait for them to put the DSL back on it. Its all rather puzzling. Could someone have nabbed the line?