POOR SERVICE ROM AVIS CAR HIRE

I recently hired a car from Avis at Cape Town International Airport. On returning the car the inspector pointed out a tiny amount of beach sand by the break and accelerator. He advised me that Avis will be charging me an additional R450.00 to remove this tiny amount of sand. He also confirmed that on return of all cars they anyway valet the cat , which would have, in my opinion anyway removed the little amount of sand that was there. On receiving my final account, Avis did charge me an extra R450 valet fee which I think is outright theft and taking the public for a complete ride. Had I known of this and had it been pointed out when collecting the car I would have had the car cleaned myself and it would have cost me only R60.00. I did query this with Avis but they refused to reconsider I will never agin hire a car from Avis - they made a very poor business decision here.