I have a huge problem here! I'm living in Munich for almost one year with Intensivkurs visa, to learn german. I got a job that match with my skills and work experience (and no German can do because they do not speak Portuguese native), but is not so related to my profession. The company really want me and filled all the papers. But the KVR refused! They said that I can not switch visa here, so I'll have to come back to Brazil (my country) to do this (and spend a lot of money with new tickets). And the Arbeitsamt also refused it (seems that I'm too skilled for the vacancy). 
I'll come back to KVR next week, because they realized that my case is different. But I have no idea about what to do with the Arbeitsamt. I tried to go there today but they was already closed. 
This happened with someone here? Anyone can help me? There is possibility to talk with someone in Arbeitsamt?
Thanks in advance!

You have to go back to your country & apply for workPermit. You cannot switch your study visa with workpermit visa within Germany.

You can go back to your country as soon as possible & apply for workpermit. Your future company can request Foreign Office to speed-up your work permit visa to get quicker.

Regards,
Pra