pepboys is not honoring warranty with work done conyers, Georgia

I took my car to a pepboys location in conyers, ga to have radiator changed back in April.  After having the work done, I noticed that my temparture gauge was still moving up and down.  I took the car back on a Saturday and was told that there wasn't anyone there who could service my car at the time.  I did attempt again on a second occassion to take my vehicle back to have them look at it on a Saturday and again was told no one was there who could service my car.  At this particular visit, the shop manager stated that I would have to come Mon-Fri if I wanted to have them to check my car out because that't when his technician would be in. 

Mind you I had the radiator installed there on a Saturday.  I then took the following Friday off to take the car back up there to have them look at it.  This tiem, I was told they had to put my car on a machine an I would have to pay for diagnostics.  I said no... I had the work done at this location and it is still under the warranty and should be covered if I'm having issues with the same thing I brought it in for.  The manager continued  to tell me no.  This all took place between July and August.  I then attempted to reach out to the district manager of this location. 

After a few days, i was contacted by him, explained my situation and he advised me to reach out to the store manager of that location.  This conversation took place at the end of August beginning September.  I attempt 4 different times to reachthe store manager and was only able to speak with him on today, 10-25-2011.  I attempted to explain to him what was going on and that i was advised to reach out to him and that I was unsuccessful in reaching him.  After continously cutting me off, he stated that he's in his store Mon-Sat and that there is no way possible that I could have called to speak with him.  Not beliving what I was hearing, I told him that I would call back in to the corporate office and let his District Manager Resolve.