Unfairly writing off my car for damages caused by Tow truck (ABSA Idirect)

I phone Absa Idirect to make a claim for a minor accident at the back of the car they organized the tow truck. On arrival, the tow driver drove my car from the yard to the road and hooked it to his van (the model supposed to be towed by flatbed). The insurance initially told me the car will be reparable with R145 000 a few days later they told me it went up to R330 000 so it will be a write-off as it was also damaged in the front underneath. I have made it clear to them that the front damages were done by the towing company as I raised concerns about how it was towed, but they insist that the car is still a write off so I must pay for it as the claim was paid less prejudice due to previous insurance history.