What's wrong with my AC?

What is your question?

When I turn on my ac or heat, it works like normal. But when I try to turn it off, the display goes off like it's off, but you can still feel and hear the air coming through the vents on HIGH. Adjusting the levels does nothing but turn the display back on. Heat won't cut off until I've hit the off button AND turned the car off.

What makes this problem better or worse?

Same all the time.

How long has your 2006 Ford Five Hundred had this problem?

About a week