Q: blower motor blows hot air but no longer blows on defrost, just straight out the dash

2013 Chevy Cruze LT RS. Defroster stopped blowing up onto the wind shield. Air gets hot and will blow either onto the floor or onto you and when defrost is selected it just blows onto you, not up onto the windshield anymore. This all happened about a week ago. The car was just at Andy Mohr Plainfield last month for an oil change. I'm not much a mechanic myself nor do I have hundreds of dollars until tax time to get it looked at. The heat/air controls are all electronic push button. There is no smell or leakage and the anti freeze is ok as well as the engine oil. The car itself is in fine mechanical condition, the durn defroster just stopped blowing up onto the windshield. I was just trying to get an idea or best guess what's going on?

My car has 54440 miles.
My car has an automatic transmission.