When you say pulls to the left is that while driving? If its while driving the first thing I would do is rotate the front tires from one side to the other and see if it pulls right. If it does then you have a tire pressure problem or a defect in the tire. If it still pulls left, find a better alignment shop. If it pulls while braking its because the front disk brakes are not braking evenly. Pull the wheels and check the condition of the pads.