I know that, Al, but since the OP was talking about Virgin's cable service and not DSL I gave a reason as to why he could not get cable services.
As I say, there are big chunks of London where you cannot get cable at all, even if the cable has been laid in the street some years ago. Also, some areas like Gosterwood Street in Deptford still only have analogue cable services, meaning you get TV and that's it. It's by no means as clear cut as people think, and most of these "dead" are old NTHell areas which were never upgraded