BMW after sales service is terrible

I have owned a BMW for 5 years and their after sales service is so bad that I am changing car brands. They do not communicate, they say one thing and do another, they request feedback but never fix anything. They keep you waiting to hand your vehicle in for a service and when collecting. I have complained so many times but nothing changes. On a number of occasions I have asked to be collected at a certain time and even though they indicated the driver was on the way I was collected more than an hour late. I strongly suggest anyone considering buying a BMW consider their total disregard for after sales service as once you have it you are stuck with them.