Parts ordered 6 months ago - no delivery/response

A door panel for my X5 (2006 model) was ordered by BMW SA six months ago. It has still not been delivered and BMW does not have the courtesy to respond or keep me posted. I have had numerous delivery date promises but when it does not arrive, I am the one asking where it is and I get an abrupt response extending the delivery date each time. I do not get any feedback from customer care although I get informed that they are supposed to keep me posted. i have had an off the record response from an internal source that the part will not be delivered and it is a tactic BMW SA uses to delay a situation until the customer basically gives up asking through sheer frustration. I have owned 5 BMW's (3 in SA and 2 in Europe) The BMW customer service in SA prior to 2002 was immaculate as is in Europe. BMW customer service in SA nowadays is worse than that of a back street used car dealership in my opinion. This lack of service stems from top management and filters down. I will never buy a BMW in SA again although I am a loyal BMW driver but recently we bought a Mercedes instead as an additional vehicle and the customer service is immaculate - what one expects of a German luxury brand.