Mbux is in the updated GLC just released, if you google MB online portal it will allow you to sign in using the details you have registered for mercedes me app for your phone.
I would call customer services as I had same issue with dealer regarding map update, they told me I had latest maps. I called customer services and they told me there was an update, they phoned the dealer for me and the next day I received a call from dealer and they had just received the update!.
2017 GLC AMG43 premium plus, night pack, leather, intel lights, 360 camera, side steps. = sadly gone
Now GLE450 Premium plus, Selenite, Black/White Nappa leather, Tech plus pack, Driving assistance pack, Tow pack, Off road pack, 22 inch wheels.