Did they do a DYNAMIC balance? There are many of the tire stores that insist on not putting weights on the outside of the wheels because customers complain about the looks of this and about them scratching their wheels. The tire stores solution is usually to balance them STATICALLY with weights ONLY on the inside lip of the wheel.
When the wheel is balanced statically, adding weight ONLY on the inside edge of the wheel makes the DYNAMIC balance worse. When the wheel is dynamically imbalanced it wobbles. With these sensitive suspension systems, this wobbling is transferred trough to the steering wheel.
I expect that if you go look at your wheels, you will find no weights on the outside of the wheels. I have gone through this so many times with the tire stores and gotten so frustrated, that I bought my own wheel balancer. I can now run any of my cars to 100MPH and they are as smooth as silk.
To properly balance with weights on two planes, you have two choices to do this without scratching the wheels; use the two piece MB weights that have a clip, they will not scratch the wheels, the other way is to use a regular weight on the inside lip and then use tape weights on the inside diameter as far outboard as you can get them. Some of the latest balancers can even place these tape weights behind the spokes where they are not seen.
If there are indeed no weights toward the outside of your wheels, you need to find a cooperative shop that will DYNAMICALLY balance your wheels. I will almost guarantee that this will solve your problem. Getting them balanced properly will be a challenge unless you throw in the towel and buy a balancer like I did. Stick to your guns with these guys and get it done right.
Best of luck,