The thing is dealerships are run by people. And as such mistakes will be made, and failure in communication will result in problems. Due to the sheer amount of BMWs they sell and service, socal dealerships are more prone to "mistakes".
Patience and clear communications will go a long way in resolving a situation. And like many have said, treat them with respect and they will also treat you with respect. It isn't right as they should treat the customer with respect regardless but that's just how things are. I know for a fact that dealerships will favor you if you've been nice to them in the past.
As for software updates. If you don't need an update do not get one! Progman is constantly changing and sometimes the latest update will cause more issues than it fixes.