Hi @Nigad
Firstly to clarify between permits and visas. In Germany, there are different types of immigration documents. The general term is ‘Aufenthaltstitel’. One type of Aufenthaltstitel is a visa (Visum), another is a resident permit (Aufenthaltserlaubnis).
Students cannot work with a visa, only once they get their residence permit. You had a visa and now have a temporary Bescheinigung (I presume the full name of what you have is ‘Fiktionsbescheinigung’). The Bescheinigung extends the validity of your visa and so you are still not allowed to work.
There is unfortunately little help we can offer here on this matter. Your university will have some sort of student support services (probably called something like ‘Studentenwerk’) that can assist international students in dealing with the authorities. You do need to allow some time for things to be processed. You mention everyone in your city getting their permit within three weeks. But you have moved cities and as you wrote, one delay was the previous city not forwarding the application. You also write ‘Yesterday, I again emailed him but still he is avoiding my email’. You need to allow some more time than this before you can consider an email being ignored. I understand the situation is frustrating, especially if you need to work to support yourself. I can only advise to follow the procedures of the local immigration office. If it is not possible to go and speak to someone without an appointment, then I would not go and attempt to do this. It would be much preferable to get support from your university student support services to speak with them on your behalf.
Best,
Éanna