I too, have had mechanical problems with two separate vehicles (both with less than 40K miles on them) and rude, untimely service by the service department.
Unfortunately, this attitude of disrespect for the customer permeates the BMW Financial Services Department as well. (It's a long story but I was bullied by the finance manager at the dealership where I leased the vehicle, thought I got the situation resolved only to have them change my monthly payment (due to their own error, once again) THIRTY months later, without notifying me. As I was doing electronic billing, I simply didn't notice the payment amount had changed until the second month that they were doing it. You have to watch your back when you own a BMW! They're not only out to get your dollar but also your peace of mind and your belief that humans are inherently "good." I distrust anyone associated with the BMW brand at this point!
I sympathize with your frustrations!