Before you go on about demanding % price cuts don't you think you should find out about what percentage of the income was profits.
Exactly how many new customers signed up with British Gas in that period to increase the profits, obviously they didn't think British Gas were overcharging.
Secondly is that a pre-tax figure or net if it-s pre-tax you are asking the government to take a cut in the money they get from British Gas.
Where do they make the shortfall up, increase income tax perhaps. Bet you wouldn't be happy about that.