Find out what the nearest priced package is for new customers (after the introductory offer) and then contact them via webchat to complain that you're paying x amount more for an inferior service and that you feel ripped off and are considering moving to Sky. Full House bundle is £70 a month after the first year for new customers and that's better than what you have, you might be charged £50 installation fee but you'll save money in the long run and have a better service.