Dissatisfaction of Customer Service and complaint handling

The first Car rental agents are not properly trained and they misinformed me about the fuel fee. When I asked the Employee what does the fuel admin fee mean he explained to me that my insurance will be covering the fuel spent on the car meaning that if I return the car with an empty tank my insurance Will cover it. According to his explication and I asked specifically he mention that. First car rental has now taken two fuel amounts out of the deposit but I was under impression that the full amount will be payed. When I phone and queried they said the employee who handed the car over to me has been dismissed. So clearly it is a lack of training from first car rental side which my insurance Santan uses. I am disappointed and dissatisfied with them and their ability to account for mistakes. I wish to get my refund of 1300 plus back. My case no is *** and the agent I spoke to was Khetiwe. I wish to get some sort of remuneration for the misinformation given by the qualified first car rental employee