Generally when an automobile part, such as a tire, causes an accident a comprehensive policy would cover damages that resulted from the accident but not necessarily the replacement cost of tire.
Not knowing the specifics of your accident or insurance policy it would be best to contact your insurance agent and get a detailed explanation of why they do not feel that the damage to the car is covered at this time. If you had recently had the tires or rims put on you might also contact that shop to make sure they were installed properly and are not responsible for the tire issue that occurred.