It sounds like they screwed up the balance. Your best bet so to have a better shop balance them.
The shop that changed my tires on the SDL warped my front rotors, which are getting thin. The MF's used an impact gun to put the wheels on.
After I clearly instructed them not to, serves me right for dropping my car off and going to work.
They also ****ed up the balance. I should have went back and told them off for the impact gun thing. Morons.
I'm just never going to go back again, its not worth it. The front rotors were getting replaced this winter anyway.