The issue is establishing the value of your car before and after. That value is what a willing buyer will pay to a willing seller, the legal definition.

The insurance company doesn't want your car and you aren't forced to 'sell' it to them. The discussion should be on its present value and the repair cost. It's a simple calculation, repair cost plus salvage value (what a buyer will pay for the damaged car, i.e. wrecking yard,) compared to value before the damage.

Your policy has a provision in it for arbitration, each of you choose an arbitrator and they choose a third, all of whom debate each of the values, the third one being the 'tie breaker'. It's binding should you care to go that route.

Don't know where you live but if in a temperate area, or hot, drive the car, park it in the sun with the windows closed. You'll be amazed at how many of the dents will pop out on their own.

I used to adjust insurance claims in Texas many years ago. On these types of claims, which were many in that area, we would be swamped with them. Delaying the handling and following the suggestion above, minimized and sometimes eliminated the damage completely.