Outsurance - Unsatisfactory Service

About a month ago I was involved in an accident, whereby the car behind me hit me after she was hit from behind. This was at a point where I was standing dead still due to traffic. A claim was laid, I submitted 3rd party docs and so forth - this was after no contact with me was made from outsurance and their client refused to cooperate, I had to do the calling around and the constant follow up. After trying for a whole week, the consultant finally contacted me and seemed very excited to let me know that they will not be covering my damages as their client was not the cause of the accident, despite the fact that she hit me. According to them, that's not how it works, the person from behind needs to pay all damages. The agent was very smug and even giggled at a point. The agent then proceeded to say I should just claim with my insurance.

I'd like to know how this is the case, because their client is liable to me and whoever hit her will be liable to her. Had she been adhering to the following distance, she never would have hit me.