Automatic Transmission Torque Converter problems of the 2012 Chevrolet Camaro

Having problems with torque converter when trying to accelerate.

The contact owns a 2012 Chevrolet Camaro. While driving at 45 mph, the vehicle started to jerk violently. The failure recurred numerous times. The vehicle was taken to a dealer where it was diagnosed that the torque converter needed to be replaced. The vehicle was repaired; however, the failure recurred. The manufacturer was made aware of the failure. The failure mileage was 17,000.

At rpm's approximately 1200-2000 car stutters, like it needs to downshift. Happens at various speeds when applying gradual acceleration. Dealer service says no error codes found, that this is "normal" on the 6 speed transmission & that because of all of the computer components, the transmission naturally lags. Seems to be problem in the torque converter?.

In may, started to feel a vibration/shimmy of some sort when accelerating in all sorts of speeds. Took vehicle to dealership and they could not duplicate. Vibration/shimmy continued and gradually become more frequent so took vehicle back to dealership in June in which the tech test drove and was able to duplicate the issue. Was told he was not the transmission expert so they had the so called transmission expert test drive and he was unable to duplicate the problem. Took my car back to the dealership the very next day and it was determined to be the torque converter. The transmission had to be flushed due to metal shavings in the transmission. I have had continuous problems with the transmission since the torque converter was replaced. The transmission is hesitating when attempting to increase speed, it slams into gear, downshifts when its not suppose to and the vibration is slowly starting to come back. Dealership is claiming this is normal for the type of transmission I have and its operating as designed.