general problems of the 2008 Toyota Scion Xd

Approximately 1 month ago, I had exited from the freeway and came to an intersection. As I pressed the accelerator to drive through the intersection, the car stalled. I turned the ignition to the "off" position and put the car in "park" inorder to attempt to re-start the car. The car continued to crank even when I took my hand off of the ignition. I had the car towed to Toyota to diagnose and fix the problem. Invoice indicated that battery was changed and that tech performed ecm calibration and fuel injector service. One month later, I was driving on the freeway at 55 miles an hour and my accelerator went out again. The car rolled down the freeway unable to accelerate until I managed to steer the car to the right side of the freeway and pulled over. I turned off the car and tried to restart the car. Again, (like in the first incident) the car continued to crank without starting. I again had the car towed to Toyota for car service. It is currently in their service department. The service tech did tell me today that he believes the problem may be with the fuel level sensor, but not sure. This needs to be investigated thoroughly as this car has stalled (without warning) on me twice while on the road, once in an intersection and once on the freeway, which puts myself, my family, and others at high risk for a collision.