2013 INFINITI JX Engine And Engine Cooling Problems

SUDDEN LOSS OF POWER WHILE DRIVING HAS HAPPENED ABOUT 5 TIMES IN A YEAR. ALMOST CAUSED A MAJOR ACCIDENT ON 1/15/14 CAR WENT FROM 55 TO 30 AND WOULD NOT ACCELERATE HAD TO PULL TO THE SHOULDER AND TURN OFF THE VEHICLE TO RESET - SERVICE AT INFINITY COULD NOT DUPLICATE PROBLEM AND DIRECTED ME TO CONSUMER AFFAIRS - CONSUMER AFFAIRS SAID AFTER ALMOST A MONTH - THEY DENIED MY REQUEST FOR A REPLACEMENT SINCE "THE PROBLEM COULD NOT BE DUPLICATED THE VEHICLE IS DEEMED REPAIRED". INFINITY ONLY TEST DROVE THE VEHICLE ONCE IN THE MONTH IT WAS THERE. EVEN IF THEY CANT DUPLICATE IT I FEEL I AM PUTTING MY FAMILIES AND OTHERS LIVES IN DANGER. THEY ARE FORCING ME TO RETURN THE LOANER CAR AND PICK UP MY VEHICLE. I SEE THERE HAVE BEEN A FEW COMPLAINTS FOR THIS PROBLEM AND I'M LOOKING FOR WHAT TO DO NEXT?...