transmission jumps or hesitates when cold

I purchased the car used, with 13k miles, from a reputable Chrysler dealership. Within the first three months of ownership, the drivetrain bolts sheared off, which wrecked the drivetrain, transmission, front differential, and exhaust components. All was repaired under standard warranty. One month after replacement, I took it back in and reported the transmission jumps from gear to gear and did not shift smooth at all, with symptoms worse when car was colder, but did not completely go away when warm. I was told the car "had to learn how I drove". Fast forward 14 months after replacement and issue has become slightly worse, to the point where it is noticeable at highway speeds. Chrysler tech reports he doesn't notice the issue, while service representative clearly agrees with me that for an 8-speed transmission, it jumps and searches for gears incorrect.