All they have done is masked the problem and as the tyres wear and weather becomes colder it will reappear, tell them to order the parts. MB put a time/mileage limit on fitting the all weather tyres and I would imagine will do the same on the knuckles.
2017 GLC AMG43 premium plus, night pack, leather, intel lights, 360 camera, side steps. = sadly gone
Now GLE450 Premium plus, Selenite, Black/White Nappa leather, Tech plus pack, Driving assistance pack, Tow pack, Off road pack, 22 inch wheels.