Autozone DO NOT STAND BEHIND THEIR PARTS WARRANTY Nashua, New Hampshire

We have been purchasing Auto parts for our Dodge Caravans for years from Autozone and without incident.  We have always been able to return parts that were under warranty.
They have always stood behind their warranty, by allowing us to purchase the new part and swap it out with the old part. I did business with them for years, only because of this warranty.
I found out yesterday that their warranty program  is only as good as their files and their manager.
I tried to swap out the old rotors that were under warranty, and they would not do it.
The manager, who was clearly inexperienced, found it VERY difficult to relate to the problem.  No matter how I tried to explain it to him, he could not comprehend my words.
He also was unable to explain to me, why he would not return these rotors.
I ended up walking away without a refund and with the old rotors.  I walked away dumbfounded, confused and with my old rotors and still not knowing why he would not take them back.  I was also angry because this inexperience, manager implied that I was lying and trying to rip them off.

The manager kept accusing me of trying to return 2 month old rotors, that were clearly years old.
I kept trying to explain to him that they were years old and covered under their warranty.  That two months ago, we purchased pads and rotors for the front and swapped those items out already.  That these rotors were from 1-2 years ago.

What my husband found out later was that they only had a record of purchased rotors from 2 months ago and that was why this manager kept implying that I was trying to return those and pass them off as 2 month old rotors???????????? I never told this guy these rotors were two months old!  Who was he to make up a story and accuse me of trying to rip off Autozone?
What I now know is rather than listening to my words, this manager kept referring to his records.
The records only showed one purchase, rather then the MANY sets that we have purchased through the years.  We owned two caravans and used autozone for all of our repair parts for 13 years!
He had no other records for us.....or at least he was unable or unwilling to find them.
So, where are my warranty records? Why was he only able to find a few purchases from months ago?

So, heed my words folks, AUTOZONES WARRANTY IS USELESS IF YOU DON'T KEEP YOUR RECEIPTS AND IF THEY DO NOT ENTER INFORMATION PROPERLY OR IF THEY PURGE/LOOSE YOUR RECORDS. 
We had warranty records under three numbers that I know of because we changed our phone number and because one attendent typed the number incorrectly.  And who knows where all of other other warranty information is?  I can't find the receipt, but even if I could, would Autozone stand behind the warranty if it wasn't in their system?  I doubt it at this point.
So, I am stuck with the old rotors because he will not take them back.
I believe that they are still under warranty and he should assume that I am honest and that there has to be a logical explanation, rather than treating a longterm customers with such disrespect!
I don't like being treated like a criminal, by an inexperienced manager who does not know what he is talking about!
I have been doing business with this company for many, MANY years and would appreciate being given the benefit of the doubt, rather than having the manager rolls his eyes at me while accusing me of trying to rip him off!
I will NEVER do business with Autozone again unless they make this right!