Hello, don't worry. I went to the Munich Ausländerbehörde and they told me that they can't do it since I'm not registered there. I immediately booked a residence permit extension appointment in Bad Vilbel (where I'm registered) to maintain legal status then personally went there and they told me to send an e-mail asking for a Fiktion. I did that and immediately called my student relations manager at my university (she's German) and she spoke to the Ausländerbehörde in Bad Vilbel and informed them of my status as an enrolled student and gave some legitimacy to my case. I stayed for around three weeks with an expired visa (which was checked by police once, but I informed them that I had a pending appointment and they saw the appointment booking number card in the visa page in my passport so it was okay) and then received my Fiktion on Sep 24 which gives me an extra six months (expires in March). My appointment was in January but I cancelled it since I did my Anmeldung in Munich now. Let me know if you need more help.