1998 Ford F Series (light)

I HAVE A 19'98 FORD F150 THAT CAME EQUIPPED WITH FIRESTONE 235/70R16 WILDERNESS HT TIRES. ONE OF THOSE TIRES STARTED TO SEPARATE ABOUT TWO WEEKS AGO. I HAVE REPLACED THE TIRES SO THE SAFETY ISSUE HAS BEEN DEALT WITH. HOWEVER, I'VE TRIED TALKING TO FIRESTONE ABOUT THE TIRE SEPARATION & THEY AREN'T THE LEAST BIT INTERESTED. THEIR DISTRICT MGR ( BOB ) SAID THE TIRES ARE SIX YEARS OLD AND I SHOULD BE HAPPY THAT I'VE GOTTEN THAT MUCH SERVICE OUT OF THE TIRES. THEIR STORE MGR ( MIKE HEMEL ) IN CHARLOTTE NC SAID TIRES SEPARATE WHEN THEN GET OLD. AFTER A 30 SECOND ANALYSIS OF THE TIRE HE SAID MY VEHICLE WAS OUT OF ALIGNMENT WHICH CONFORMS TO THE FIRST RULE OF BAD CUSTOMER SERVICE => BLAME SOMEONE ELSE. I OFFERED TO KATHY SMITH ( FIRESTONE CORPORATE) TO TAKE THE VEHICLE TO MY NORMAL MECHANIC AND HAVE THE ALIGNMENT CHECKED UNDER THE SCENARIO THAT IF IT IS MISALIGNED, I WOULD PAY THE BILL & IF IT IS IN ALIGNMENT, FIRESTONE WOULD PAY THE BILL. SHE DECLINED MY OFFER, AGAIN SUGGESTING FIRESTONE REALLY IS NOT INTERESTING IN GETTING TO THE ROOT CAUSE OF THE PROBLEM. I DO NOT KNOW ANYTHING ABOUT THE RELIABILITY RECORD OF THIS TYPE OF TIRE OR THE PROCESS TO GET ONE OF YOUR SPECIALIST TO ANALYIZE THE FAILURE MODE OF THIS PARTICULAR TIRE. I HAVE ALL FIVE OF THE OEM TIRES, ONE OF WHICH IS THE SPARE ( NEW CONDITION ) I'M MORE THAN HAPPY TO MAKE THESE TIRES AVAILABLE TO YOU FOR ANALYSIS; BUT, I'D RATHER NOT KEEP THESE TIRES AROUND FOR VERY LONG IF THIS IS SOMETHING THAT YOU BELIEVE DOES NOT WARRANT