Did you have trouble with these pads playing the chords pre-assigned to them, or just assigning your own, new chords?
The reason I ask is that several people have found issues with the pads when they first get their M3's which can all be solved simply by running a pad calibration function (Global P0, drop down menu, Pads Calibration).
If you had already ruled this out then I apologise in advance, but this info could help others having to send their M3's back and losing some enjoyment time
Happy New Year to you all.