transmission box

Audi A5 2017 gearbox in limp mode after I change oil put it in any Gear still won't move after I drain the oil out of my Audi I put back 4 litre inside the box I could not put any more start running out I was told 7 litre should be in the box I tried to put it in gear it did not move i put it in D and reverse and it still won't move is anyway around this time I doing something wrong