I have been advised that from 15.10.11 my broadband package will increase by £5.00, (£20.40 now). I assume this is a Virgin Media plan to stop the National Broadband. Can I complain to anyone?
Why do you think it is a plan to "stop the National Broadband"? Putting their prices up potentially gives them more money to expand/upgrade with. Also, by putting prices up it makes it easier for other providers to compete with them so potentially increases the competition in the area and therefore could increase availability.
If you want to complain then I assume you would complain to Virgin. No-one else sets the prices for them. And obviously you have the ultimate way to complain which would be to leave and move to someone else if there are others who can provide for your needs at a lower price.