Petrol attendants ripping us off in the name of "I made a R100 mistake" *******.

I was at this service station on the week of 18 Feb 2020. I asked for 95 unleaded worth R500. The petrol attendant after sometime he comes to me and tells me he made a mistake and poured petrol worth R100. He poured another for R400 and I left. I thought that my mind was playing games with me. I went again on the 26 Feb 2020. I asked for petrol worth R1000. It was a different attendant and the same thing happened. A Mistake of R100. I made noise and asked if it's their modus operandi. The guy poured R900. I will never use that petrol station again. Because we are being ********** at this petrol station and people are not noticing this. This attendants make R100 from each car and pretend it's a mistake. I hope more people come forward and lay complains against this stupid people.