2016 SCION IM Engine Problems

PURCHASED MY 2016 SCION IM AND WAS GREAT FOR THE FIRST YEAR. IN 2018, THE CAR DEVELOPED A ROUGH IDLE, USUALLY AT A STOP LIGHT AND AFTER THE CAR WAS WARM. I REPORTED IT TO THE DEALERSHIP AND NOTHING WAS FOUND AS IT WAS NOT REPLICATED DURING THEIR TEST DRIVE. THE CAR CONTINUED TO ROUGH IDLE UNTIL THE NEXT ISSUE HAPPENED. THE NEXT ISSUE I HAVE BEEN HAVING IS THE TRANSMISSION WOULD HESITATE AT STOP LIGHTS. IT ALSO DECELERATED ON ITS OWN WHILE TRAVELING AT 70 MPH DOWN TO A SLOW CRAWL!. TOOK IT INTO THE DEALERSHIP AFTER A SCARY SITUATION ON THE FREEWAY. THE SERVICE REP TOLD ME THAT THERE WAS AN UPDATE TO THE TRANSMISSION SOFTWARE THAT HAD TO BE DONE. AFTER ABOUT 3 HOURS, I WAS TOLD THAT AFTER THE SOFTWARE UPDATE, MY CAR'S TRANSMISSION WAS DESTROYED! I WAS A BIT CONFUSED AS TO WHAT HAPPENED ON...