According to this video I found that shows how the automatic climate control functions, https://www.youtube.com/watch?v=1067_jgDIYo, it appears that the system automatically chooses where to blow the air based on the temperature you've chosen. Or you might have somehow accidentally selected the windshield or front windshield defrost feature.
For additional assistance, please find an AskPatty Certified Repair Shop at http://www.askpatty.com/search/?type=all&m=30&q=&keyword= and they can help you diagnose and repair the problem.