That sucks.
You have to use a fine saw blade when cutting that laminate and it makes a very fine dust. Even a little bit of it can spread a long ways.
Going on 2 months ago now, before we moved in to the new house, we had the old Popcorn Texture removed from the ceiling. They seal the entire house off with plastic, it looked like that scene from E.T.. They scrape it off and basically re-tape, and re-mud every joint and screw. Sand it, then apply new texture, and paint.
We still have to clean every few days because of that fine white dust from the sanding. It is still getting everywhere. You'd think after almost 2 months it would be all gone.
We think it got in to the duct work, and up in to the attic and it's just going to take some time for it to work it's way out of the house.
We're having attic insulated on Dec. 19th. They are going to seal the entire attic, air tight, from the rest of the house. Every light fixture, electrical box, and gap where a pipe or wire runs through. Hopefully that will stop a lot of it.
Right now there's only 2 ~ 3 inches of insulation in the attic. How this house made it 23 years without anyone adding any insulation to it boggles my mind. But that's another story for another thread.
Good luck getting that cleaned up Beepster. And take it easy with the back. If it's really bad, I'd consider calling them back.