2017 NISSAN FRONTIER Seats Problems

I'VE NEVER FEARED FOR MY OWN LIFE AND THE OTHERS I HAVE TO ROAD SHARE WITH UNTIL OWNING THIS 2017 NISSAN FRONTIER. I'VE HAD IT INTO THE DEALERSHIP A TOTAL OF 7 TIMES BECAUSE THE DRIVERS SEAT SLIDES BACK AND FORTH WHILE GOING DOWN THE ROAD. THE NISSAN DEALERSHIP HAS REPLACED AND TIGHTENED UP THE TRACK THE SEAT SITS ON AND WITHIN A FEW HUNDRED MILES IT BECOMES LOOSE. I'VE CONTACTED NISSAN AND THEY REFUSE TO TALK TO ME. NOT ONLY DOES THE DRIVERS SEAT SLIDE BACK AND FORTH WHILE GOING DOWN THE ROAD BUT SO HAS THE PASSENGER SIDE. I TOOK IT BACK TO THE DEALERSHIP I BOUGHT IT FROM 2YEARS AGO AND THEY REFUSED TO HELP ME OTHER THAN OFFERING ME TO TRADE IT IN AND PUT SOMEONE ELSE'S LIFE IN JEOPARDY.