I have had my vehicle serviced multiple times at Kuni and find them to be very professional. in fact I have bought two cars there in the last seven months. I did have an issue with my Bluetooth phone that is actually not on the approved list and they were able to pair it and make it work without any issue.
If you have a problem with their service why not take it up with the service manager rather than voicing it to BMW? The dealer is there to take care of us and getting the proper relationship is very important. No body is infallible and I can't imagine that they want to lose your business.
Give them a call I think his name is Brent.