Watch out for GB Energy price hikes!!

I have just had email from GB wanting to put my monthly contribution up from £82 to a massive £149 - over 60% increase!!! There is no way my consumption has increased by this much and after an hour wait on phone I was told they had been instructed by OFGEM to increase monthly payts - what a load of rubbish!! GB had no justification for increase and couldn't answer my questions and eventually agreed to an increase of £100 which is about right in my estimates. I think they are trying to get everyone off of their fixed crystal tariffs because they are unsustainable financilly but I am staying till my tariff ends. I am posting as I can't bear the thought that others will not object to increases and GB energy will get away with this daylight robbery!!!