More than likely they had the incorrect cone setup for your wheels when they put them on the balancer and when they spun they looked bent.
That was my thought also. Discount Tire (whom I worked for many years ago, lol) has good trainers and bad trainers. Not all of the "techs" know how to properly use the balancers and will just use whatever cone that seems to work properly. If the cone is making contact with the center cap ends of the wheel, it will appear bent while spinning. Cone must only contact the hub area only.