Kopal Milling Clamps

[magicniner]

In all they are pretty good clamps but you have to torque them up more on anything than a good clean edge especially on a HMC.

It's common in industry to misuse and abuse equipment that is used outside it's design parameters but to describe that as a fault of the equipment rather than operator error is unfair on the product.
The correct solution to your problem would have been custom feet for the clamp noses which incorporated spherical contact surfaces to allow free alignment of a lower section with 3 distinct high points allowing clean 3 point contact on uneven surfaces, the rep sounds like he had no engineering background or problem solving capabilities beyond "big spanners" and when all you have is a hammer, every problem looks like a nail ;-)