I have a 2008 Rav4 Limited. Last year I lost control of where the air flow comes out for heating and cooling. A repair shop took apart the dash and said I need a new heat box. It was all busted up. However they threw away the part before I could see what it was and now the air doesn't come out of the dash at all. It fluctuates between the front of the dash and tge floor. Since there is no part named the Heat Box. I don't know what I am looking to replace. Please help.