Fletcher's Tire & Auto Service Would not honor warranty brake job on the 3rd failure since they done the job originally Marana, Arizona

Originally Fletchers auto and tire completed a brake job on my SUV which had a warranty.   About 2 months after they completed it; my brakes started jumping or bumping when I tried to stop so I took it back in to them.  They said they needed to do something so they fixed them "again" and everything was fine until about 2 weeks ago; then it started doing the same thing AGAIN!!!!   
 
I called them and they said the have some of the information in the computer of all my visits (doing the 2nd repair) but they couldnt find the original brake replacement of exactly what they did (why would fix the brakes the 2nd time if you dont have records of what they did?  Which by the way the replaced the rotors w/new pads, etc).     

Unfortunately I cant find my original receipt so I cant provide that to them.   The warranty is still in effect, they have records of all my visits including the last repair (at no cost to me). I called them and they instructed me to come in at which I did. They said they would take care of it.
 
I drove 50 miles to get there and after about 10 minutes they came out and told me they were not going to fix it!   This is a safety factor, they have records of the two visits (the 2nd was no cost to me) so I tried to reason with them but it got me no where. 

I hope no one ever goes to their stores to do any business.   This has been a horrible experience and now I have to go to a reputable repair facility (never another Fletchers again!) and pay the money to them when this should have all be covered under warranty.    I will tell all my friends and family exactly what happened to me and warn them not to go to a Fletchers store again.