From what I've read, Virgin Central IS part of the L package, but you have to go to Virgin Central and press the red button and the content there will be free (the other VOD content, except for Catch Up Tv (and Virgin Central) is not). If you access Virgin Central from the VOD menu, it will not let you have it for free. If the red button is not working, you'll probably need to get that sorted before you'll be able to enjoy Virgin Central
Hope this helps