I think the problem might be that the rims are aluminum. And the nuts are steel. As are the studs. The problem is not the nut being too tight on the stud. But the hole in the aluminum rim galvanizing (as said above, Galvanic action... is kinda like electrolisis)
to the OD of the nut.
It does take heat to break the nut loose from the lug holes in the rim. But really, all they need to do is apply a small (as in just warm) the area of the rim around the lug nut. The heat opens up the hole enough so an impact wrench can loosen the lug nut. A good shop should know that. A bad shop would apply way too much heat, and screw things up even worse. But the shop you took it to should know that. So find a good shop.