Alamo car rental

Dispute of Claim # *** On March 11, 2018, I along with 2 other travelers went into the Alamo Car Rental office to pick up the car that I had reserved online. I was told that I needed to upgrade to an SUV, because the car that I had reserved would not be sufficient to drive in the mountains. So I upgraded to an SUV and purchased a $500 damage waiver. The desk clerk noted that there was a scrape on the front side bumper. Before we got in the car, although the parking lot was dark and unlit, we inspected the car with the light of my cell phone and noticed the car and front side bumper had substantially more damage than a scrape, so I reported it to the attendant. The desk clerk said it was noted, but didn’t bother to go look at the damage. There are 2 previous Damage Inspections and Ready Slips showing fb dent, w/s chip, scrape fb and fender. All of this damage was not noted on my inspection slip, but apparently had not been repaired. The car was nowhere close to being in pristine condition
On March 16, 2018, I drove up to Alamo Car Rental to return my car. As we got out of the car, an attendant approached me and asked for the key. We proceeded to unload our luggage from the back of the vehicle. I asked the attendant if I should wait there while he inspected the car. He looked over the car and said “No you’re good. You can go to the office.” I checked out and assumed that there were no issues.
Later, I got a call from Alamo Car Rental. The person on the phone stated that there was damage to the car. I was at the airport getting ready to board my plane. I told them that there was previous damage. There were 2 passengers as well as myself, and none of us saw any damage other than what was already there when we rented the car.
I received another call from Alamo. They stated that they were filing a claim. I told them there was no additional damage to the car when it was returned. They said the alleged damage was minimal and would not exceed the $500 waiver that I purchased.
On June 5, 2018, I received a letter stating that the damage exceeded the $500 damage waiver and that I owed an additional $639.57. .
I am disputing this claim for the following reasons:
If customers are to inspect cars before taken off the lot, it is only fair to have sufficient light. I was unable to take picture or a video of previous damage for this reason.
I along with 2 other people in my party inspected the car and reported extensive damage that was listed as a scrape on inspection slip to the attendant before we left the lot.
All previous damage known by Alamo should be listed on Damage Inspection and Ready slips. There was front fender damage that was not listed. Although this is not damage listed on this claim, it was damage that was not acknowledged by Alamo at the time of rental. So I’m questioning whether the damage in this claim was not acknowledged as well.
At drop off, the inspection should have been done while we were present, since we were more than willing to wait.
Photographs of damage were taken 4 days after the car was turned in.