They definitely shouldn't be sitting in pools of wet. Do contact the company now and appraise them of the situation so that they have the info on file. Take pictures as proof of the problem areas and keep a set for yourself if they originally offered guaranteed work. When the ground thaws, if they still won't correct the problem, you can on all but the biggest trees perhaps, lever the root balls up one side at a time and insert a few good-sized rocks underneath. If the root ball is still fairly loose and moveable, repeat on the other side, replace any lost soil and water it in well.
We've done this many times here, so if you think you'll be doing the work yourself and wish to have more levering advice, just holler out.
