To answer the question you have to look at the conditions. Ofgem, unlike their French and German counterparts, do not cap prices. There is no upper price limit in Britain which is why the French and Germans bought our power companies so they can charge what they like here as they aren't allowed in their own countries.
On top of that the EU make our government make a 10% or more green tax on all bills to subsidise wind and solar power which wouldn't sell in an open market as it costs many times more and only produce power occasionally. Every single condition underlying the price is rigged to make them rise indefinitely with no restrictions and as all three major parties both impose green taxes and will not regulate prices then it will continue as long as people keep voting them in. it's your choice at the next election.