Disgusting service and daylight *******

Yesterday I went to fill R200 diesel from Shell Select in Montclair and had a quarter tank. Somehow my gage did not move up at all after the guy filled my car, I realized this on my way back home and decided to go back there to confirm if they did indeed fill my tank as nothing happened. The entire staff there attacked me and was so rude saying my car needs servicing and I should not trust the gage since I got the slip. I said please fill another R200 just to see if what they are saying is true as my car had been gone a service recently. They filled another R200 diesel, and the gage went up to half tank. I was so confused as they had insulted me and attacked saying I am making false accusations but now they could not explain to me why the gage actually went up the second time around if the problem is with my car. They still said I am mad and that I need help coz it was filled an there's a receipt to prove it. I am absolutely dismayed at the service I got from them as well as the level of disrespect I had to tolerate from the entire staff defending themselves for nothing. My car is still missing the 8 litres of fuel they claimed to have filled.