daylight *******

I fill up my Polo, which usually takes 36 - 39 litres on average, depending on how low I run my tank. Today I filled up at the ENGEN in Roeland Street and couldnt believe that they filled up 46 litres ! The tank was not even remotely as empty as usual and they also didnt fill it to the brim, as I stopped them beforehand suspecting something strange going on. When I confronted management that the tank only takes 45 litres, I was just told that the car always has a reserve of 7 litres and I cannot prove how empty it was when I filled it. This is not true, as I run a logbook which shows that in the 5 years of having that car, I never managed to fill more than 39 litres. Management would not budge though. I generally find the petrol attendants very friendly at this station, but will certainly not go there again, as this is daylight *******. They overcharged me by approx. R 200.