Reliance General Insurance - Car accident claim is not approved completely

I have a car policy with Reliance General Insurance with policy no - ******************. My car met with an accident on **th May ****. While taking a right turn on a four-lane road, another car while crossing the road banged into the front door of my car. Due to sudden brake, the two-wheeler banged from the back of my car. Now the Reliance General Insurance has approved only half of the damage. The damage on the back side has not been approved. They have rejected the claim saying, " the damage is not justified. " After spending our hard earned money on car policy, I have to justify the damage. They are not even ready to accept the argument. They do not have any logical reason for my claim not being justified. They said, "there is no impression of the tyre of the two-wheelers, so it's not justified that the two damages happened at the same time". This is so absurd. Even if there is an impression, how can one say that the two accidents happened at the same time? And I gave my car for repair after * days of damage. My car is washed every day. How can there be any impression of the tyre of two-wheeler? I am cheated by Reliance. When I have paid the full amount for the policy, why should only half of my damage be approved?