Insurance does not pay full damage amount

Hello dear reader, after an accident with sheet metal damage I have some problems with the insurance of the other accident participant. To the accident: I wanted to turn left into a parking space and then put out backwards again. Because oncoming traffic was, I stopped to let it through. When I entered the gap suddenly put the left-hand vehicle back. I was already almost competent in the gap, however, the vehicle hit me still just behind the Kotf From the police I got a report of irregularities and the possibility to comment on the outcome. My accident participants were immediately predicted that this would be expensive for them because they were driving backwards without looking. After I wrote my statement about the accident, this report was withdrawn against me! I therefore think that I could explain completely my innocence in this accident. The insurance, however, pays me only half of the from a car factory My question now is: May an insurance company argue so, although according to the police, I am not guilty. I have already filed an appeal with the insurance company and would like to call a lawyer in case of need. I can only misjudge how my chances of doing so are and would like to see further costs. want to avoid the damage, because the damage amounts to about 1200 euros and my car is not yet so old, that I wanted to repair the damage only urgently. I would look forward to one or two answers. Thank you in advance and many greetings Andreas