Today i finally found the solution to my problem

maybe not the prettiest one ,but it works
The idea of taking the dashboard apart didn't suit me at all, so i removed the glove box and started to look for something that caused the problem and the problem was in this lever . After i pushed on it , air started to flow from the top vents

yay !
I didn't go into details where that lever goes and what drives it . What i did it's just secured it with the screw

Problem solved