Bad customer service

I bought a Hyundai Venue in 2022,went to Eastern Cape for a weekend, I noticed while driving on the free way when pressing the brakes the car vibrates, I reported to the sales man where I bought the in Germiston, he said I must trade it in, I have been complaining about the same thing since 2022,until today, I went to the branch again the technicians said the is nothing wrong with the car. Went there again this year Jan while doing service asked them to check it again ,they then said the is nothing wrong with the car, the manager said I must go to Lombard tyre's Alberton and ask his brother inlaw he is very good with cars, I was so disappointed because I expected him to escalate the matter to his seniors, but all he cared about was for his brother in law to make money out of me and all they wanted at the dealership was for me to trade in the car not to fix the problem.