It may seem unfair, but in reality the profits the greedy buggers make isn't from forecourt sales. It's mostly from other sources.
If you understand that a barrel of oil has gone up in one year by 80% - that's EIGHTY PERCENT - you can better realise the problem. Added to that the tax levied on petrol/diesel is the highest in Europe, if not the world.
I'd suggest to the powers-that-be to invest heavily in alternative forms of vehicle propulsion. And soon.