Damaged transmission

I took my q7 for service at audi polokwane,my car was in a perfect state.They inspected the car and gave recommendation to change things like bulbs,oil filter.I then told them to do a normal service like changing the oil filter which wasn't available by that time.i then asked them to order one for me then took my car.on my way home i noticed that my transmission gear couldn't allow me to perform automatic,i then called them immediately and was told to bring it back.fortunately the oil filter was delivered as well then they were in a position to do car service.<br> I asked them to test the transmission as well.When i came ba k in the afternoon ,i asked them about the transmission and was told that they've tested the transmission and it was fine.i took the car again and realised that it had the same problem and used manual which made the key stucked inside the ignition as it couldn't recognise p(park).i went back to audi whereby i was told something us wrong with the transmision which wasn't detected whilst inspecting the car and again i never had a problem with upon inspection.one of the technician confessed that there was nothing wrong with the transmission.they damaged my car