Yeah, they might have come with the wheels but it doesn't mean they're any good! Also you probably ruined the bolts and/or the threads in the hub by over torquing them if that's how you tightened them. 120Nm is the torque for a vw wheel bolt, which should be pretty easy to undo with the standard issue wheel wrench. You didn't say if the bolts had sheared or just undone themselves either....