MBENZ Constantia POOR Service

I Have booked my ML in 9 months ago for a brake issue. They replaced a part and charged me R40K, which I duly paid UP-FRONT. I received the vehicle back drove it for a day called them to advice that the problem has not been resolved. I returned the vehicle to the dealership, and took them a further about 2 months to check, replaced another part and requested a further R20K. This is for an issue that was not resolved, but now I must pay again. In addition they damaged my sun roof and the reassembly on the centre console was skew. I pointed this out immediately when I got into the vehicle. This does not show great workmanship or pride. Further to this I reported the matter to MBENZ SA with no results from them. Lance the Customer services manager (MBENZ SA)has not even had the curtesy to return my call. I have called them 4 times to try resolve over the last 4 weeks. NO RESPONSE from MBENZ SA at all. When I reported the matter to MBENZ SA I got a reference number and requested that a copy of the complaint is emailed to me "by their recommendation to do so" I did not even receive that email. I have left 2 messages for the dealer principle to contact me with NO RETURN call.