Engen *****s your fuel

I went to go put R100 petrol into a 2017 Smart car this morning at Engen Main Road Convenience Centre. The fuel light went on this morning. I put the petrol in at 08:17. I didn't see the counters change on the tank, and thought it was odd. But the guy brought the card machine and I paid. As I drove off I noticed that my fuel light didn't go off or changed at all. I took a photo of the fuel gage 2 minutes after putting in petrol as proof. I called Engen but the manager refused to listen to my story and just said if I got a slip it os not possible. I explained that R100 falls my tank half, and R200 makes it almost full, so the fact that the light didn't even go off proofs nothing was put in. Further more when I went to go take my purse out of the boot I didn't hear the petrol being poured which I also found odd, but thought the attendant will still switch it on. I went back to Engen and asked them to put in R100 as proof, and my tank filled up to the half way mark as usual. The manager still insisted then it is because my car now had R200 in it. He was very rude, and wouldn't hear me out. He said it happens a lot at that station, but that it is the customers that are always wrong. I think this fuel station are *****ing from customers, and getting away with it. Be careful and try to avoid that fuel station. Check your tank, slips etc.