Terrible service after returning the car!

Europcar Cape Town airport - Extremely helpful and inviting when looking for a car but they add on additional charges upon return. The person i was dealing with via email - Naniki - was rude and kept quoting their terms and conditions. I returned the car with a full tank of petrol and this was acknowledged by the inspection guy upon return yet they still charged me for a 'petrol top up' and an admin fee for the top up?! Money making scheme of note!