2013 GMC YUKON DENALI Engine Problems

LIVE IN ARIZONA. WAS DRIVING IN AUGUST 2018 IN AFTERNOON VEHICLE FAILED TO ACCELERATE IN INTERSECTION. ALMOST GOT TBONED. TOOK TO GMC DEALERSHIP. WE WERE SO SCARED AS WE HAD OUR SON IN THE CAR. DEALERSHIP KEPT FOR A WEEK KEPT TELLING US THERE WAS NOTHING WRONG I WOULD NOT ACCEPT THIS FOR AN ANSWER I TOLD MY HUSBAND TO TELL THEM THAT WE WERE NOT GOING TO PICK UP THE CAR COULD THEY PLEASE HAVE A MANAGER LOOK AT IT AT THAT POINT WE ALSO ASK THEM TO REPLACE ANY FLUIDS AND DO WHATEVER THEY COULD TO MAKE THE VEHICLE AS SAFE AS POSSIBLE AS THIS IS OUR MAIN VEHICLE AT THAT POINT WE WERE GIVEN A BULLETIN THAT WAS PUT OUT IN 2015 STATING THAT THIS PARTICULAR CAR HAD THIS ISSUE AT TEMPERATURES ABOVE 110 DEGREES FAHRENHEIT AND WHEN A DEALERSHIP WHY GMC DID NOT RECALL THEY INFORMED...