Deeply disappointed in how an elderly customer is treated

I am so deeply disappointed by Budget insurance's service. I have a car insurance policy with Budget, and due to the great service I had been receiving, I successfully convinced my mother to join Budget insurance as well.

Yesterday, after multiple attempts made to get through to the call centre to make a claim, her claim was rejected over the phone. My mother had an accident due to bad roads and potholes but the car was still driveable. She then took the car into the dealership for inspection since it was due for service anyway, and they found that the radiator had been knocked and they made a report for her insurance. Upon calling Budget insurance, the agent told her that comprehensive insurance does not cover such because this is a mechanical fault and should make use of warranty services with her dealership. Now, how is damage due to an accident a mechanical fault or warrantee matter?

I feel like budget insurance is taking advantage of this situation because this is an elderly woman, and how do you just reject a claim on the spot without even assessing the report from the dealership and the car itself?

This is creating unnecessary stress for an elderly customer who has no claim history or defaults on her payments. At this point, I regret convincing my mother to switch to Budget