Car rental Rg. is not taken over

About 2 weeks ago I had a traffic accident, I was not to blame. A short time later I drove to the dealer with the request to hire an expert to tell the damage, that was on Monday afternoon. On Tuesday afternoon I was prevented because of operational difficulties, so that I could not leave the rental car, so that the loan of the company Europcar extended to 3 days overall. I have now decided not to have the vehicle repaired. The insurance company now informs me that without a proven repair it is not possible to take over the costs. In fact, I see that 3 days are not fully paid, but one for the purpose of obtaining an expert report should not be a problem, or I have to draw up an RA first, which I did not exceptionally. My vehicle was ready to drive.