FORD KA MK II, brake discs and blocks through at 32,000 km

Hello, I have a Ford Ka, Bj 06/2009, he now has about 32,000 km on the speedometer. For 3 days I noticed during the last braking process, that my “brakes” are grinding at something. Yesterday I was at the friendly dealer, where I also bought the car and I thought I was hit by the blow. The monader looked at the car with me and tells me that the brake blocks and discs were already through. I was completely shocked and asked if he explained to me. I drive from the “country” to the city to work, every day about 18 km easy, I also do not latch full on the brakes, so I brake normal and none of my traffic lights and can run through accordingly well. Is it normal that with this km-performance the discs are already through? At the already after 25,000 km the crossbars could be r. Request for your reports