Welcome to X5 World.
I've had horrible dealer experiences here in Korea and I don't speak Korean (can you imagine the frustration multiply exponentially with the language barrier). But I think I demanded too much. I expected that because I owned a BMW, that I should be treated like I own a BMW. Well, EVERYONE coming to the service center owns a BMW and some own one that more expensive than yours. So it didn't work out to well, especially when a guy drives in his M5 and parked it next to my 3-er

.
So, I found a new service center (since I've successfully managed to alienate the other one) and became more compliant. Now, I wasn't a pushover, when I wanted something done quickly, I still demanded it but I do it with tact.
What do I get for being agreeable?
My car was once picked up (from my garage) by a service center representative and a '07 525i was left as my loaner. Now, BMW Korea has a limited pool of loaner cars to hand out to ALL of their service centers. So, getting one is a PITA.
So far, my experience with my 'new' service center has been great. I've befriended the Service Center Manager and I'm A LOT more compliant now because I know I don't want to piss this guy off and because I know he'll try his best to take care of my car.
Find one that will take care of you.