Headlight Switch problems of the 2002 Audi A4

One day I received a message in my info center about "left dipped headlight" and an icon flashing with an "x" a the stick-figured bulb, went out to the front of the car and noticed my left bi-xenon was out, but my right one was not. Turned the lights/car on and off, once turned back on, still nothing, switched the right bulb into the left side socket, turn the car on, still no light coming from the "left dipped headlight", I immediately went to google this problem when I arrived home later that day, and I found a lot of post all over the internet about this problem with Audi car lights going on and them bringing it to the dealer and the dealer telling them they do not know what is wrong, so I went for myself and they told me that they received this problem before but do not know how to treat it, but for $500 they can order a new headlight and for $200 a new bi-xenon lightbulb and $200 labor we can replace the whole headlight unit. They wanted me to pay $900 for light to come out of my car, even though I paid $40,000 for a car to already do that. Besides the point, they do not know what is wrong with it, I would say a couple hundred people have this problem from all the posts I've seen and also all the people that have not posted anything. Its very dangerous due to the fact after my left one had gone out, my right one had also gone out later that day but came back on after a few tries. But that's a total blackout I had on the highway, I mean it should be a recall if Audi knows about it and doesn't know what to do about it. Please help!.