Bad service

I am a third party on this claim. My car was knocked on the passenger side by discovery client who ignored the stop sign. Police report was done. Every part of the accident pointed to the other car not stopping at the stop street. I had the right of way. But discovery says. Both parties are at fault and they won't cover this claim. Are the people who are insured with discovery really know what discovery is doing. Not paying claims. Making it your own fault. My question is. What is an insurance company for???. Just to make money.