you had the tires rotated, did they put the old air gun on it?? if so they probably warped the rotors...... i have the cheap Auto zone rotors put on my car and never had any trouble with them, but then i never let them put the air gun on my car.. when needing tires i take one off and bring it to the place and take it home and put it on and use a torque wrench to put the torque back on the tire........
also check the air pressure when getting tires they put 50 lbs in mine and i always have to take some air out.........
