No help or satisfaction from Mercedes- Inyanga Empangeni Kzn

My Mercedes A ********** model has had a terrible noise on start up. Inyanga Motors - Empangeni KZN have had the car at least 10 - 15 times to try to resolve this problem over the past 3 years. They have now told me it is normal. This is NOT NORMAL. Surely I should have a detailed account of what the noise is, and if no logical conclusion , then the transmission must be removed and sent to the experts for analysis for repairs . I am tired of hearing it is Normal.