If you are truely dis-satisfied with the stat, you should call the contractor now and tell them you have used the stat and can't completely understand how to operate it. Tell them you have read through the instructions and it just seems to complicated for you.
If the contractor that did your work is a good, reputable contractor that stresses customer satisfaction, then swithing the stat will be no problem for them. The company I used to work for did it all the time. Mainly cause our salesman loved them Lennox Sig stats. No-one, including myself sometimes, could fully understand it. We changed a lot of them out.