Dollar rental car charging for damages after return

Hi, this is my first time renting a car, so please bear with me.

On March 24 at noon I returned my rental car at a Dollar. They did a walk around and said the car was clear of damages.

But, on March 25, I was billed $500 for a "dent to the rear right tire". I asked for proof, and they sent these before and after pictures.

before

after

Honestly, I cannot see any damage in the pink box they drew on. They have only sent over a repair bill, and these 2 images (no accident report form, no demand letter). They will not provide any more information when I ask.

I took a video of the car walkaround beforehand, but did not take pictures of the car after returning (dumb, I know).

I paid for the car with a credit card that provides secondary insurance, but requires me to get a denial from my primary GEICO insurance first since it's below my deductible (would could increase premium?).

I'm not sure if I should dispute/chargeback this charge with my credit card company (could affect credit score if sent to collections), or if I should just go the insurance route.

Thank you in advance!