关于车祸理赔-another case

I have been here for a while to learn from other's experience. Now I meet some trouble. Here is my story.


My car was hit from back side two weeks ago and I had no fault at all. Both cars had insurance in GEOCO. The obvious damage in my car was at back bumper. But I also found the big noise when driving and one of safety light was out of order immediately after the accident. The GEOCO guy only paid money for replacing the damage bumper with a used one, and said the noise was not the result of the accident. He said it was because of the rust on the exhaust pipe. I am a girl and this was my first car ( I am a student) and my first accident. I don’t know much about the car. So I accepted what he said and is trying to find a shop to repair my car. But today when I drove home, the pipe fell down suddenly. I was scared by the noise made by the pipe touching the ground. I want to ask two questions:
1. Is it reasonable for GEOCO only paid money for used bumper instead of a new bumper even though my car is ten-year old?
2. Can I claim the pipe loses? Or I have to check my car in some shop to prove it is because of accident?
Thanks for your attention. Any suggestion is appreciated.