Engine Burning Oil problems of the 2006 BMW 530

I have a 2006 BMW 530i that has been leaking oil for 3 years. I have had work done on the car from an authorized BMW shop and the leak was not fixed. I have had excessive oil consumption to where I have had to either put oil in the car myself because it was at the minimum level, or take it in to the dealership (if I'm in the area) for them to top it off. I have taken my car back to the dealership 4 different times and they have told me that they could not find an oil leak. Recently I took my car in for an oil change and they told me I had a leak in 3 different places. Since I have been told different scenarios, I escalated the issue to higher management and asked for an answer as to why two different mechanics at a dealership that specialize in the "ultimate driving machine" gave me three different diagnostics. They then told me that my car has a broken bolt which is common for this model, but refuse to rectify the situation and the vehicle is under extended warranty and neither will pay the cost.