2012 FORD E-250 Wheels Problems

VEHICLE HAD FOUR NEW TIRES ALL OF SAME BRAND AND SIZE ONE OF THE TIRES HAD A BLOW OUT, REPLACED THE TIRE WITH NEW TIRE OF SAME BRAND AND SIZE. ONE WEEK LATER ANOTHER TIRE STARTED VIBRATING SO WE TOOK IT IN AND THEY CHECKED IT AND FOUND THE TREAD IS SEPARATING FROM THE CARCASS. I HAD THEM PULL ALL FOUR TIRES AND REPLACE WITH NEW TIRES OF DIFFERENT BRAND. I KEPT THE FOUR TIRES AND CHECKED FOR ANY RECALLS. THIS PARTICULAR TIRE DOES NOT HAVE A RECALL YET BUT ANOTHER SIMILAR DOES. THE TIRES WE HAVE ARE THE HANKOOK DYNAPRO AS LT245/75R16 THE TIRE THEY HAVE RECALLED IS HANKOOK DYNAPRO MT LT325/60R18. HANKOOK SAYS THEY WILL ONLY WARRANT THE ONE TIRE SHOWING SEPARATION BUT WILL NOT DO ANYTHING ABOUT THE FIRST ONE BECAUSE WE DON'T HAVE IN OUR POSSESSION OR THE OTHER THREE BECAUSE THEY HAVE NOT FAILED YET....