Dissapointing customer service from Mercedes-Benz South Africa and Mercedes-Benz South Africa

I'm convinced that Mercedes-Benz deliberately sell us faulty cars to have us pay for each and every fault which the vehicle has once its out of the dealership. The quality of service from Mercedes-Benz has declined drastically over the last few years. After having purchased a few vehicles from Mercedes benz this will definitely be the last. I bought my car in 2020 and from day 1 I've had an issue with the extreme squeaking sound coming from the brake pads. According to the dealership they have change their supplier of the brake pads. I've been in and out of the dealership to resolve this issue but each time a white paste is app**** on the brake pads and the annoying sound is back a day later. Recently my sun roof stopped operating. The dealership have refused to repair the sunroof saying it's not part of the maintenance plan. The sun roof is automated so I do not understand why I should be charged for a mechanical fault of one of their units. The sunroof is electrical so I can not tamper with the faulty component of the sunroof as its not within my reach. They've lost me as a customer