Not Complying with the BMW Estimator Report

On the 07th of August i was involved in an accident with one of the Discovery Insure clients. The driver of the other vehicle basically drove at the back of my car and damaged the rear bumper. my car is badly damaged at the back as a result of the accident. I claimed through the guys insurance as a third party and until today the claim has not been finalized. i am the one who is phoning them on the daily basis to make a follow up on the claim and nothing is happening from their side. BMW Approved Repair Center gave me a quotation of R94151.89 to fix the car and they also advised that they might be unseen damages on the car. Discovery insure is making me an offer of R35523.65. i am not willing to accept their offer because i will not cover the shortfall. I want them to book my car into a BMW Repair Center and pay for all the repair costs or comply with the BMW Repair Center quotation.