Don't want to worry you, mate of mine moved in March, took him two whole weeks to get back on line with virgin media, with his old e-mail address and phone number which he had to do for his business.
Never known him so mad could not get to talk to any body human at virgin, cost him a fortune in calls, he had been told it would be no problem before he moved, apart from that he quite likes Virgin media.
I also have to say I have never had any major problems with virgin media.