Welcome to blend door installation hell! Your blend door has broken along with many, MANY others. DO what I did, turn the thing to heat and beat on the black box underneath the passenger side dash!Worked for me, till I close on my new house with a BIG garage.
When you turn temp knob from cold to hot what sound do you hear,do you hear a harsh but low clicking noise? Or do you hear the normal thump of the door closing? If you hear the clicking then your door is broken. If your willing to spend the cash (which buying a house, I am not) then you can take her to the dealer for a costly repair, BUT if you have the fortitude to muck with the labor intensive repair on for yourself, then have fun. From what I have read about it is a bear to work on. Searcher1