I had mine done too. Dealership installed a new set of pads and it continuously making the noise.
So I called my service manager and he told me there is nothing else they can do.
Can you believe $108k M5 cannot fix the brake noise?
So after a long thought, I traded my 2013 F10 to 2013 Porsche cayenne turbo. And will never buy another BMW.
It was embarrassed to drive loud brake squeal noise...