Unhappy with VW service

I purchased a Golf 7,5 in January 2018 from VolksWagon booysens, The vehicle had 2000kms on the clock and it was assumed to be a demo. I never had any issues with the car for the past year, until it was due for 30,000kms service. The car had around 27,000kms and i started hearing a humming noise from the drive train i took the car to VW booysens for inspection as it is still under warranty. They told me the break pads need to be replaced as well as the disks. I then took the car to VW the glen to have the pads and disks changed and the noise persisted, I took it back and I was told that some hy****ic device needed to be oiled. The noise persisted and they cant find the issue. I refuse to put my fam at risk and need this matter resolved asap. VW need to come to the party and give me options as this a a new vehicle!!!!