Pethetic service where not even the manager cares!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I've made a booking through the service manager where he is suppose to change the dates I was told I would get a call from the service manager after calling him more then 10 times without a response. BMW IS this really how you deal with your clients. Pethetic for a well known brand like yours. Its the next day and still NO RESPONSE!!!!