claim rejected

I was involved in an accident where the driver of the other car did not stop at a Stop sign. The driver of the other vehicle is insured with out surance. Theother party acknowledged their fault and liability which is on the police report. My insurance has settled my claim and are now attempting to recover the cost from outsurance. They are now passing the buck to say it isy fault and are refuin to settle. This is deplorable business practice and ethics. Hope people out there see them the bad business practice.