Problem at service never solved

Serviced my car at MB Menlyn on 17 Feb. Ask them to attend a small problem at the same time. When I collected car I realised they did not fix the problem. Service manager not really interested to solve it. A week later the marketing research firm phoned to check if I was happy with service. I told them the situation and that I was not happy. Three weeks later still waiting for MB Menlyn to phone me and sort out the problem. Cannot wait for my service plan to come to an end so I can take my car to a NON MB agent and get descent service. Come on Menlyn - stop your arrogance and sort out my problem.