Terrible service

I am fuming at the service I received at the Engen Garage in Northriding, situated on Beyers Naude. I asked for 95 unleaded of 100. The petrol attendant, who I unfortunately didn't his name, poured R150. Then proceeded to tap my card without allowing me to see the machine. When my card requested to be inserted which is HIGHLY UNUSUAL for amounts less than R500, only then did I see the amount on the speed point that its R150 and not R100 as I requested. I even left without him giving me my machine. I am absolutely irritated and I will never use any Engen garage ever again!!!