Problems–> opposing private liability

On 26.6 my Passat Variant was damaged by a passing driver. He rang (know him away) and gave to the damage. He reported it to his private liability. (He should only make sure that an expert should be consulted) The next day we were in a VW contract workshop and he signed a cancellation declaration to his private liability. A reviewer was ordered by the workshop and an expert report on a damage caused by 240€ an impairment of 250€ and a downtime of 4-5 days (approx. 250€) was created and everything was submitted to the insurance company. Today the insurance company registers by post that my claim was rejected because the pictures of the damage did not fit to the damage. Now I ask myself: What is my check? Only the downtime and the downtime? Or the total repair costs and downtime and impairment? Thus the accident causer subordinates the assignment declaration ieben has and it has admitted to have caused the damage is his claim to get the repair paid by the insurance or am I wrong? Have an appointment at the Di with the insurance. Do you need your advice to know what to say!!!