Front Suspension problems of the 2003 Land Rover Range Rover

I have a 2003, Range Rover hse. The air suspension inactive warning light illuminated and the wheels shook. I took the vehicle in (12/29/08). They could not find the problem and suggested an alignment. I got the alignment and they cleared the warning light (1/2/09). I left and noticed the vehicle still felt out of aligned. Later the warning light (air suspension inactive) came on once again (1/15/09). This time the left front wheel failed to raise up. I brought the vehicle back in. This time they told me the air suspension was leaking and needed to be replaced. It cost me $2900 (1/22/09). I took the vehicle home and noticed the vehicle wheels still shook. I reported the problem but refused to bring the vehicle back in. Recently, the warning light (air suspension inactive) illuminated once again and none of the wheels would raise (2/22/09). I had the vehicle checked again and was told it was never aligned and the wheels were not balanced. I had the vehicle aligned and the wheels balanced. The vehicle is again out of alignment and the wheels shake. I do not want to get ripped off again, so the vehicle remains in my garage.