Unhappy client

I have received an extremely disappointing service from discovery insure,I got an accident and immediately report it, I then took my car for assessment and later when the repairer fix the car, I only found out that the insurance approved only one side of the vehicle... I then called them and ask they just said they are sorry for that instead of fixing the problem, they now telling me to pay double access because they only cover one motion to a vehicle...how do I pay double access on the incident that happened instantly on the very same spot,time and place....I'm not happy with how I've been treated and it's very unfair and a day light *******...