Funny sound on the vehicle after servicing

I took my car for routine servicing: 6/08/2015. About week later I noticed the funny squeaky sound as is there is something either loose or scratching. I then took the car back. One of the workshop staff drove with me and also confirmed the sound. I left the car with Mercedes Benz for the day . Later I collected it and was told everything is fine, the problem was picked up and sorted.<br> <br> Last week the sound came back, this time much louder at times. My son even recorded the sound (audio), because at times it will be quiet. I then went back on the 2/11/2015, Jassena the supervisor asked a guy called Chris from the workshop staff to drive around the residential block with me. He also immediately heard the sound.The car was then booked for 5/11/2015 (today). I dropped the car this morning. Now I am told by Amy (Consultant) from M Benz they don't know what the problem is and I have to pay about R5,000 first for them to remove the dashboard. Also there is no record on the system that I had previously brought the vehicle for the similar problem. They say that is not covered by motor plan. Amy also talks in a very unapologetically and forceful manner. It doesn't feel safe to drive.<br> <br>