Mercedes-Benz 300 Costly Repairs and Poor Service

I recently purchased a two-door Mercedes-Benz 300, and the problems just don't seem to end. Since I bought the car, there have been unresolved issues. The navigation system still hasn't been installed properly, despite five visits to the service center. Yesterday, I received a warning that the rear driving light was not working. I went to the service center today, and they charged me ₺15,000 in service fees. I haven't hit anything, and there are no cracks or visible damage. They claimed there was a crack and sent the car back without offering a replacement. Instead of standing behind their brand and replacing it for free, they blamed it on user error. You might think the amount shouldn’t be an issue for someone driving this car, but I’ve switched vehicles many times and have only driven Mercedes. It’s disappointing that such a brand doesn't even stand behind its own products.