If the bearings were bad, it seems that the brake shop certainly would have found the cause of the noise and the cause of the brakes not releasing or dragging. Bad bearings make a rumbling sound, and they would do it all the time, not just when braking. If brake pads, rotors and bearings are good. look for something else. A good shop should be able to find the cause. I would take it to another shop and see what they find.