Bac service at Audi Polokwane

I took my car for 90 000 service on Monday, 25 June 2018, and told them that it makes noise (whistle) when I apply the brakes. Man its, service advisor called to say I can collect the car around 14h00. I came late I went to tell the security quart that I will collect the on Tuesday. When I go there on Tuesday Manita said the noise was because of dust on the brake pads so they did not replace them because they are still on their (Audi)specification. When I drive the car, the noise was worse, I then phoned her on Wednesday and I dropped the car Thursday late. Friday morning she phoned me and said the technician drove the car and there is no noise. My complain is that Audi specification is for the brakes to make noise? I have been driving this car for 4 years and whenever I complain about noise on brakes, they fixed it, is this a new specification for their brand to make noise when applying the brakes?