brake pads and disc not worn out but need to be replaced on 2016 GTI

I am very disappointed with the service I have received from both the Vw Silverlakes and Vw SA as a whole . I took my vehicle a Golf 7 GTI 2016 which I bought brand new on the 29 September 2016, the vehicle started making grinding noise on the front wheels when braking of which I took it to the dealership on the 04/05/2017 which was on 13858 km . The dealership failed to resolve the noise on the wheels after four times with the same sound in a month . On the 5th time which was on 06/06/2017 the vehicle was on 15322 km I was told that the they are going to replace the brake pads at no cost because the break pads where not worn out. On the 04/08/2017 the vehicle was on 18990 km when I took the vehicle back again for the 6th time with the same noise a week later I was told that the tests have been done and that the brake discs and the pads are not worn out but the discs need to be replaced and that I need to pay for them . After going back and forth with the dealership and Vw SA , Today I was told that I need to pay for the discs because its wear and tear. To my surprise , I asked them why did they pay for the break pads when i took the car in on the 5th time since they are also wear and tear and was not given an answer. It is very disappointing after four months with 6 visits that the vehicle is still not repaired . the Vehicle has now been with them for 2 weeks .

Not expecting these from such a big Brand ....