Audi Q7 Air Suspension Issue

Hi,

I have an Audi Q7 2007, V8 4.2 Quattro. 5 days back after
coming back from a friends house i noticed front of the
car was way too lower than the back. Drove it a bit and
the car was bouncing like crazy. Took it to the workshop
the next day. At first the guy said its the compressor and
he will have to change it. As soon as he took the
compressor out and checked it he said the compressor is
working perfectly fine so its a shock somewhere. So the
passenger side shock had to be changed since it was
broken and the car was more lower on the passenger side
front. They tried to level the car through computer so the
back which was higher also went lower almost same to
the front. After changing the shock the car was only lifting
from front and not from the back then he said the motor
needs replacement after motor replacement the car still is
not lifting from the back. The front lifts for a few seconds
then it goes down as well. Could it be a faulty shock or
what please help been 5 days