I take it you have their collet sizer? If so disassemble the die and make sure there are no burrs or metal shavings from manufacture left in the working parts. Lube it very lightly with a grease, I use Shooters choice red gun grease but that`s because I have it on hand for my rifles. Any grease will do, even vasaline. If the collet body and tapered ring hang up the result will be a crushed case as you discribe. Reassemble the die and screw it down until it contacts the shellholder on a raised ram.
Now is the tricky part. I add a 1/2 turn to mine and apply pressure by "feel" to size my brass. Too much pressure though will pop the top cap off the die ruining it, so go lightly if you try this until you get the feel for it. The presses that "cam over" such as the Rockchucker can have the die screwed in ~ 1/8 turn at a time and letting the press cam over when sizeing, adjust in small increments until the brass is sized.