Mini Cooper

We are having problems with the service center at our MiniCooper dealer. How can we put forth our complaint to a higher level?

Your Owner’s Manual contains information on how to contact the manufacturer’s customer service department (or whatever they call the folks whom you can contact at corporate headquarters).

As VDC noted your owner’s manual should have that information. How old is the car? Unless it is still under OEM warranty, you should not be taking it to the dealer. Find a local independent (not a chain) mechanic.