Discount Tire Company Discount Tire joy ride damaged my truck Surprise Arizona

On July 2012 I took my truck in for two new tires to a Discount Tire in Surprise, AZ. Store number AZP51 on west bell road. The wait was not long and I soon watched them pull my vehicle out of the shop and then take off on a small road to test drive the new tires. The guy came back and parked my car in the front of the store and I noticed he seemed a like shaky when he said I was all set to go. I didn't think anything of it and jumped in to drive home. I park it at my house and get out to walk around and notice a deep dent the size of a quarter with the paint chipped out on the tailgate. I drive it back to Discount and let them know that they damaged my truck. Of course the man says that none of his guys admit to any damage on my tuck and that I could file a damage report. He said that this damage report can only be filed by a manager. The manager was not working that day and they told me to come back later that week. I came back on 3 different days and no manager. I thought that was ridiculous. The fourth time back they finally had a manager working. He filled out a damage claim report on my truck and notified me that I would get a call from the corporate claims department about getting the damage repaired. 3 days later I get the call dorm the claims department that they are sending an appraiser to value the damage on my truck. The appraiser from Saguaro Claims Services calls me to setup a time to come look at the damage. He shows up to my office at work and I meet him outside to tell him about the damage after I got my truck back from Discount. He takes pictures and writes notes, then tells me about the process of how they will take the tailgate off replace the whole tailgate piece and out new emblems on. He then said that during this time they will give me a rental car until the work is finished, shakes my hand, then says I will get another call with the details about when this repair will get scheduled. I do not receive a call but receive a letter from Discounts Claims Managment Dept -

Dear Mr xxxxxxx,

The investigation into the above referenced claim is now complete. According to the independent appraiser's report and review by Discount Tire there is no evidence that any tools used or service provided by Discount Tire damaged your vehicle on the date of service July 14, 2012. For Discount Tire to issue any type of compensation, the company would have to be found legally liable for the damage to your vehicle. At this time, we found no legal liability on the behalf of the company. Based on this information Discount Tire is not accepting liability for the damage to your vehicle and, will not be issuing any voluntary payments at this time.

If you have any additional information that you think may be relevant in our liability investigation, please submit it to my attention for review. In the absence of any new information, our file will remain closed. Please be advised that the statute of limitations for property damage claims in the state of Arizona is 2 years from the date of loss.

Sincerely,
Xxxxxxxx
Claims Mgmt Dept.
Discount Tire Company

So basically any Discount tire shop employee can take your car out and damage it, give you the keys and tell you that if you can't prove it, then deal with it. I don't understand why the employee who did the damage just didn't tell me about the accident? They have insurance to cover accidents that happen like this. Instead they would rather just say "prove it". With all of the expenses of my wife having a baby last year, I obviously cannot spend hundreds of dollars to fix this damage. Now I have to look at it and get angry at Discount every time I walk to my truck. Considering is spent over $500 for those new tires i would expect them to cover a few hundred dollars to fix the damage they did and then I would have continued to buy those tires from them moving forward.