Just changed from our price protector to march 2017with Npower and it will save us approx £480 less per year.
Really easy to do.
I just rang the lowest quote with no tie in which was GBenergysupply and it was all done within 5 minutes. 0800 6444 451.
The big 6 take the mick. Npower alone has about 30 different tariffs, they are getting away with confusing people and the general apathy of people who can't be bothered to change.