Wheels trembling, brake caliper balancing?

Servus Forumsgemeinde, I’m frustrated at the moment: Ride a Mercedes CLA Shooting Brake, EZ 12/2015 in first hand. After about 10 months my MB-house changed the brake discs and pads, because of steering wheel tremors when braking on bulwark. For 2-3 weeks I have weighed the steering wheel tremor at approx. 120km/h. Last week tires. No success. Reclaimed, re-examined: “Everything is fine: tires and rims run super without impact”. Again unsuccessful, the tremor is still there. dealer thinks it could be due to an imbalance of the brake caliper. I should complain to Mercedes. Mercedes, but also other manufacturers would have all the problems with it. Be present at the friendly time. I would also be interested in an assessment from the forum. Can someone provide a useful tip? Thank you for your efforts. NG Jürgen