It is well known that duties on oil petrol diesel is above 100 why does Indian government not waive off duties instead of rising prices?

It is well known that duties on oil petrol diesel is above 100 why does Indian government not waive off duties instead of rising prices?
The duties are needed for social/civil/government spending and programs already in place, that if not funded with it will need to be funded by some other tax.

Lowering the price to the consumer on petrol increases demand, works against conservation of resources and therefore can at to increase need and price overall...and any profit it that change would likely be kept by private industry not really scene by the consumer, while the gov't still receive less.