Being ****med into paying for a service covered in my Motor Plan

My mortified by the Mercedes Benz dealerships, I took in my car in Sandton for a service and they didn't change my break pads as they were making noise because apparently from the service advisor they no longer change all break pads for all vehicles they just clean them and put them back. Due to asbestos being harmful to the Green Economy that's now the Mercedes way and I was also assured that the noise will quiet down. However it got louder. Then decided to take the car to Constantia Mercedes as they managed to change my brake pads the last time. Then the service advisor told me I am not covered for them anymore as I have used all 4 break pads they provided. I was shocked because I only changes break pads once the last time they skimmed them when they did my Brake discs. I want that proof which they cant even provide and I want my brake pads sorted. The lies