Refuel chargers after returning the car refueled.

I was charged for refueling after returning the car refueled I even after supplying a slip I was told everything is correct. Their reply was very condescending.

This was their response : We have investigated and found the no anomalies with the refuelling process on your rental . Your point of view regarding the fill is understandable however it is our responsibility to hand you and the next customer a vehicle that has been filled to the same standard, therefore we have to physically refuel.

In this instance the vehicle allocated to you uses an average of 5.5 litres per 100 kms under general driving conditions and you drove 209kms which ideally should have taken +/- 11,49litres. Our total being 16,25litres we are a little high, which depending on driving style, speed, etc. is acceptable both ways and with all due respect we are not criticising your driving but rather explaining our variables.