Leasing and liability damage

after an accident that I did not blame, I gave my vehicle (leasing vehicle) to my dealers and agreed with him that you should only carry out everything you want to do with my vehicle after the cost acceptance of the insurance. this was also not a problem because of the insurance in writing a 100% cost assumed commitment was available. now to my problem, the dealer commissioned a reviewer with the assessment of the damage (approx. 1,500 euro grosso) and led Dara cost for kfz-damage, rental cars and expenses were also replaced by the insurance so that the accident was actually done for me. now after almost 11 months! I get a warning from the expert because the insurance paid him the expert honorar not with the reason …..that with such a low damage height no opinion was necessary. what should I do now? I did not even see the opinion bz. it bauft 1. does the insurance have to pay the fee? 2. if no, do I have to pay it without having it commissioned? 3. is a 1 reminder after 11 months not something (to)late? thank you, jochen