Inflated invoice/overcharged

I hired a vehicle from the king shaka branch on Saturday. I dropped off the vehicle on Monday. Before dropping off the vehicle, i fill the vehicle with petrol. I advised both the attendant and office official at the king shaka branch that i had filled petrol in the vehicle. I even handed the petrol slip to the attendant and took a copy of it for my records. I now received a final invoice which reflects a refueling charge of R171. 55. This is ridiculous! How can tempest charge me refueling when i had already fill the vehicle. The petrol station was next to the king shaka, so the car was full of fuel. Contract No: TKSIA ********** RA5/TKSIA ********** RS6