Please assist

I made a booking through Travelstart and an amount of R1264 was deducted from my credit card, I received a voucher confirming my booking and showed my payment and it states payable at counter R0. When I got to the counter to pick up my car the agent stated that I have to pay R1264 when I return the car, I showed her the voucher showing that I have paid, she said that the payment does not reflect on their system therefore I will have to pay again. Can someone please assist in sorting this out. I tried but the lady did not know of any agreement with Travelstart.