How to clean this oil spill stain from driveway if council cant help?
You could investigate trying to spread a layer of the dry clay type cat litter over the spot and grinding it down into the surface with your foot. If there is any residual petro/oil material there that has not reacted with the asphalt road surface the clay material should absorb it and help to clean the surface. It may be necessary to leave the clay material there for a day or so. If you see some improvement after sweeping/vacuuming up the first application you may want to try a second or third iteration of the treatment.

A final stage of cleanup with water can be aided by using a soap such as laundry detergent and a scrub brush. The soap will emulsify the oils and allow some of it to be washed away with the water. 

In the case where the spill has actually had a reaction with the asphalt it may be very difficult if next to impossible to remove the spot.