Out of the cities, filling stations either have diesel OR petrol. Not normally both.
Identifying the difference is easy. If there are trucks in the place, it is a diesel station. Or if the ground around the pumps is heaped with dirty sand, and looks like a skid pan, its also a diesel point.
The price of fuel is ridiculous: less than a couple of pence per litre.
Fuel pumps in rural areas only have one readout - the quantity dispensed. There is no price indication. Brush up on your arithmetic before getting your wallet out as the attendant will wait for you to give him the right amount of money, or read into your body language, whether you expect change.