Virgin Media

I hate Virgin Media, I can't remember why I started (I'm sure it was before the junk mail started), but they're certainly giving me no reason to stop. My girlfriend moved house about 8 months ago. Her previous house had cable and so she signed up with Virgin. When she moved she weighed up the option of paying to get out of their one year contract but decided to continue with them on ADSL for the remainder of the 12 months at her new place. That 12 months is now up, and due purely to their shit performance of streamed BBC content I recommended O₂'s excellent ADSL offering. So she called Virgin today to get her MAC only to find that when she moved they restarted her 1 year contract. Is that legal? Can the contract be binding?