Owners/service Manual problems of the 2018 Chevrolet Colorado

5/20/18 ac issues -- starts blowing cold then warm/humid then back cold. Inform service advisor when took truck in (6/18/18) for service. Tech not find ac issue. 8/7/18 truck in again -- ac starts blowing cold air then puts out warm/humid air then back to cold air. -- temp is set 72 and outside is 85 - why do I have to put on auto to get cold air to blow out or adjust down to get? why on auto it wants to freeze us at 72 and temp has to be adjusted up? tech monitor doors with ac running & were working as designed -- note they report wam to cold - not cold to warm to cold as I reported. Well the issue still holds and the truck's climate control (blending process) has as issue in getting the temp adjusted on startup. 2/18/19 - on my drive yesterday with my wife, truck temp set at 74 and outside temp was 54 and 40 minutes into drive the vehicle fogged up the side windows and I had to turn on defrost. Then that evening as temp had dropped, when turned on truck it blew hot then cold then back to hot. The blending that the system is doing is not working correctly. Need to go back to the manual ac/heat control!.