No show at Mercedes

Unfortunately I can't rate zero stars. My vehicle has been with Mercedes Sandton for 4 weeks now, for roof repairs. I have had to go to site to find out who's responsible as I was getting no correspondence on the status (maybe that's because nothing is being done to the car). Upon chats with the service advisor, the workshop does not have the expertise to fix my vehicle. While we have so many unemployed youths in our country, one of the biggest brands in the world can't capacitate anyone to have this skill??? It's really appalling that I'm approaching 3 months without my vehicle and Mercedes seems to be the blocker from unavailable parts to no expertise...