Charges extra 5c to 10c

I would like to know why does Engen Westgate convenience Centre. Parklands, Cape town always charge an extra 5c. Well, it's no longer 5c it's 10c. The owner has been doing this for years. If I ask for R250. It will be R250.10. No matter what the amount. Its always that extra 5c/10c

No matter how we complain the owner ignores us. Seems the staff knows all about the extra and they can't do anything about it. We get the same story from the owner. His pumps has not been updated. I refuse to pay that extra 5 or 10c. I paid it before thinking it will come out the petrol attendance wages. But now I no longer will. I would at timed fill there 3 or 4 times a day. How many 5c and 10c are the owner *****ing.

Engen Petroleum need to have a look into this.