Poor BAD Service at Mercedes.

I took my vehicle recently for service and asked to check why my rear wheel is slowly going flat.from 05:00 my car went in for B service- I got a call to collect my car at 17h00( at same time they tell me thjey close 17h00-When I received my car , just drove out to mall, my tyre warning came on again! I took it to tyre place who spotted crack on inside of my rim.Now I had to beg for a quote to replace..>.R16000 for Rim and R>2000 for labour to remove wheel and replace!! and had to come from Germany 4-7 weeks , but my calls found x3 in JHB 3 days away! The after sale service is really poor compared to other car dealers..Its like they afraid to share information - "this is what you need , and this is what we are going to charge you "- No personal service at all!