Unfair judgment

I logged a claim last month around thee 11 th of October , my car burnt and I don’t know what started the fire .. the insurance took the car and it’s was written off .. on the 19th of this month after several calls I made , the rejected the claim and the reason was the car had poor maintenance , but they never assessed the car before, my question was how they came to that decision and one one is giving me an answer and the consultant told to go and get my car myself and their report says the claim was rejected and the case has been closed