2005 Nissan Sentra Tires Problems

ON 10/04/07 I BOUGHT A LEMANS CHAMPION HR BL 195/690R15 88H TIRE FROM FIRESTONE COMPLETE AUTO CARE BUENA PARK. ON 11/1107 I NOTICE THE TIRE WAS FLAT I CHECK THE TIRE FOR ANY HOLE OR TEAR'S I COULD NOT FIND ANY. THE PRESSURE OF THE TIRE BEFORE I REFILLED IT WAS 19 PSI AFTER WARDS IT WAS AT 31.8 PSI. I CHECK THE TIRE PRESSURE 10 DAY LATER ON 11/21/07 IT WAS AT 25 PSI. I TOOK IT BACK TO THE STORE TO BE REPLACED. I TOLD THEM WHAT WAS GOING ON THEY RAN SOME TEST AND COULD NOT FIND ANYTHING WRONG SO THEY DID NOT REPLACE THE TIRE. I BELIEVE THERE IS A DEFECT IN THIS TIRE. *TR

REGARDING THE BRIDGESTONE TIRES ORIGINALLY INSTALLED ON MY CAR - THE CAR WAS PURCHASED ESSENTIALLY NEW OFF OF THE LOT IN 2005 (300 MILES). IT HAS THE ORIGINAL TIRES - BRIDGESTONE P195/60/R15. IT NOW HAS ABOUT 2000 MILES ON THE CAR. THE LEFT FRONT TIRE BLEW OUT WHILE DRIVING AND HAD TO BE REPLACED. THE TREAD AREA HAD APPARENTLY SEPARATED FROM THE SIDEWALL - A SPLIT ABOUT AN INCH LONG. THERE IS ALMOST 1/2" OF TREAD ON THE TIRE, AND THEY APPEARED FINE UNTIL THIS APPARENT SEPARATION OF TREAD AND SIDEWALL, BUT THE TIRE COULD NOT BE REPAIRED AND I HAD TO BUY A NEW ONE. *JB