It’s saddening to say but even a reduction of 50% in the duty (or a cessation of VAT) will only be for the short term.
Ultimately, oil is a commodity. It is traded on the open market with laws of supply and demand driving the basic cost per barrel of crude oil.
Extracting crude oil from the ground and refining it requires energy and the cost of the energy to do this is increasing rapidly as we all know.
Take a long hard look at the big financial institutions in this world who essentially trade in commodities like oil and make a profit from doing so.