Misled and poor service

I took my x trail in for 75000km service, since I bought the vehicle in august 2018 I was told on the 101 check that the vehicle is in a very good state, they only replace the brakes on the vehicle, but during the service I received a call that they need to replace my front brakes I told them no it's no need to replace it because it was replaced 4 months ago but the service advisor told me the brakes need to be replace because its been worn out, So I was misled how can new brakes only last 4 months (8000km). and when I collect the vehicle I was just handed my key with no invoice or to tell me what they have done, not very friendly. I will also take this to the ombudsman, if is this the kind of treatment we received from NTT NISSAN BLOEMFONTEIN I won't buy my next vehicle from them.