Will they replace the unit or the parts? Is it under warranty? Because if it isn't, then you're out of luck. The only way I know to decrease rear camber on a torsion beam car is to either raise the car or to mandrel bend the beam, and I don't know if any local shops have the proper mandrels for it.

You have to talk long and earnestly with your Honda dealer about this problem, because if your car is new, most likely it's an assembly fault at the plant. If your car is a few years old, they can always argue that it was caused by damage to the torsion beam.