Unfair, short deposit paid back, terrible after service support

Rental Agreement Number: E***

I rented a car in January from the 3rdh to the 14th at the King Shaka branch, they took a 3500 deposit, when I returned the car, the guy checking it didnt say anything, a week later I received a mail saying that the car was dirty, there was a few blurry photos that showed some sort of chappie on the floor at the back, I am unsure if this was done by my kids, but after speaking to them I was accepted the charge of R600 for a valet to speed up my deposit payout. When they paid my deposit back they paid out R2000 and some change, I queried this with them they said they would get back to me, I followed up a week later and they send me a mail saying they will get back to me by the 12th, it is now the 18th and I am still waiting.