2007 GMC C6500 Tires Problems

I JUST RECENTLY PURCHASED A 2007 YUKON. THE TIRES ARE GOODYEAR WRANGLERS (P265/70R17). I MUST CONSTANTLY INFLATE MY TIRES ON A DAILY BASIS AFTER BEING PROMPTED BY THE MONITOR SYSTEM. THE TIRE PRESSURE GOES DOWN TO 27 PSI AND IS SUPPOSED TO BE AT LEAST 37 PSI. I ONLY HAVE 6900 MILES ON MY SUV, BUT NEITHER THE CAR DEALERSHIP NOR THE WARRANTY WANTS TO REPLACE THE TIRES. I HAD A FLAT ON YESTERDAY ON MY FRONT PASSENGER TIRE. I WAS TOLD THAT THE WALLS WERE TORN BECAUSE OF DRIVING ON LOW PRESSURED TIRES, BUT WAS TOLD FROM A TIRE KINGDOM REPRESENTATIVE THAT I RECEIVED FALSE INFORMATION FROM MY DEALER. HAS ANYONE ELSE EXPERIENCED THIS PROBLEM? *TR