Martin Lewis has a thing called Cheap Energy Club, or similar. You input your details and energy consumption, and the site finds the best tariff, based on the information. Then, you agree to a switch and they do the rest. Also, when your deal ends, or even if there's a better deal before that, they email you. Win win.
Thanks. I have swapped to Sky, the full package, including sports (DH) and movies (DC and me!). £54 per month (currently pay £80!) and £197 cash back. I know I could get cheaper without the full package, and may change if we don't use enough to justify, but it's hellish cheaper anyway for a year.
No mention of a MAC or PAC when I signed up!!!