I hate to be the bearer of bad news, but the contractor is correct. Cracks in concrete is normal, especially around a pool where the can be great pressure put on the deck. Stamped concrete is any stronger or better than plain conrete, just prettier and unfortunately, it cannot be repaired. You can go ahead and confront the contractor but he will win if you want to take him to court, so long as he worked in good faith. The symptoms you mention do not appear to be caused by freeze/thaw conditions, just settling. Perhaps you can show that the ground was improperly tamped, or that inadequate expansion and control joints were used, but there is little in the area of standards for pool deck construction.
A much better for your pool deck would have been to pour plain concrete and have it resurfaced with Sundek Concrete coating. It would have been much cooler than concrete, slip resistant, mildew and stain resistant, and repairable should it have cracked. It also would have cost much less.
The Sundek dealer closest to you might be able to help with what you have, if your contractor fails to do anything. I think the closest one to you is either Washington DC or Baltimore. Check their web site at www.sundek.com for more info.
In case you wondered... I am A Sundek dealer...in Georgia and have several hundred satisfied customers that glad they stayed away from stamped concrete.