Not responsible for accident, but have to pay access

On 12 December 2019 a truck reversed into me at a toll gate near Brits. I got the driver's details and went to report the accident, to get a case number. A representative from the company the driver works for, phoned me the next day, requesting photo's and the case number of the accident. He informed me that they are willing to pay for the accident. Today is the 12 of January. I was informed this morning that I have to take my car to Autogen, in order to get it fixed. I have to pay an access of R5200 out of my pocket, according to Virseker. When I asked why the Third Party was not contacted yet, I was told to speak to their Legal Department. I was informed that the case was still being investigated and that I had to pay the access, before they cold try and recover it from the Third Party. To say the least, I don't have R5200. I did not cause the accident. The Third Party is willing to pay, so what is the deal here? I am for sure cancelling my membership with Virseker.