2007 JAYCO TRAVEL TRAILER JAY FEATHER EXP Tires Problems

PURCHASED 4 TIRES NEW FROM DEALER IN JUNE 2016. ON 7/18/16 ONE OF THE TIRES BLEW OUT WHILE ON THE INTERSTATE. I RETURNED AND SPOKE WITH DEALER, "NO WARRANTY, PROBABLY HIT ROAD DEBRIS". I THOUGHT, "WELL. OK, AND I PURCHASED EXACT SAME BRAND TIRE AS REPLACEMENT. ON 3/23/17, A SECOND OF THE NEW TIRES BLOWS OUT ON THE INTERSTATE. THE FIRST TIRE HAD LESS THAN 300 MILES ON IT; THE SECOND LESS THAN 700. UPON GETTING 2ND TIRE REPLACED OUT OF TOWN, THE DEALER EXPLAINS THE DATE CODE INDICATES THE DATE CODE ON THE "NEW" TIRES SHOWS THE TIRES WERE 5 YEARS OLD WHEN SOLD TO ME AS NEW. HOW DO 2 "BRAND NEW" TIRES FAIL CATASTROPHICALLY AFTER MINIMAL USE? IS THIS A TIRE PROBLEM OR WAS IT THE AGE OF THE TIRE WHEN SOLD AS NEW (DATE CODE 4111)? EACH BLOWOUT CAUSED DAMAGE TO MY TRAILER/CAMPER REQUIRING REPAIRS. I...