I'm pretty sure that you won't actually be the charged for the period you have no service, why do you think you will?
According to the woman at PN they will carry on charging me.
As I'm sure you can imagine moving is a lot of hassle anyway - not helped by the fact that I'm moving over 200 miles.
Now I have to try to book this in on who knows what other day, which will probably delay it weeks.
The most annoying thing is that if I hadn't phoned they would not have seen fit to tell me they had decided to do the install on the 6th. The phone is still going live on the 2nd, apparently 4 days gap is still a simultaneous provide.