How to complain about a business in Berlin

Hi all

I have heard that businesses in Berlin (and Germany generally) have to be licensed by a municipal department in order to operate legally.  I have also been told that it is possible to make a complaint about a business where they act in a way that is detrimental to the public.  I am trying to find out how or where I can complain about a business that offers property management services in Berlin.  Any ideas?

My guess would be here:

http://www.vzbv.de/go/