Welcome to the Wefugees community. I understand that dealing with German authorities can be quite frustrating, especially if you don't speak the language.
As you may have seen, this platform mainly focuses on asylum proceedings and on questions around refugees arriving and living in Germany. So I'm not sure this is the best platform to share your experience - it might be helpful to reach out to an expat/ student platform where Canadians exchange living and arriving in Germany!
However, I had a quick look for you and found this more detailed explanation on what to do to apply for a Youth Mobility Visa by a Berlin Service website: https://service.berlin.de/dienstleistung/305265/en/
The website states that applying for this visa while you are already in Germany is possible, so that shouldn't have been a problem. Please scroll down on the website and look at the form "Antrag auf Erteilung eines Aufenthaltstitels" in English. Did the form you filled out look like that? If you are certain that the forms you filled out were the wrong ones, reach out to them again and explain that issue.
The fees for the residence permit for the Youth Mobility Visa are €56 and the visa will generally be issued on the same day, as the website states. However, it's 44€ more for issuing the electronic residence permit (eAT) = 100€ in total.
You're not a student there, but it would probably be fine if you reach out to the international study service of my university, who support people with questions around visas:
Visaservice | Internationales Büro
Internationaler Club „Orbis Humboldtianus“
Unter den Linden 6, Raum 1071, Erdgeschoss
Tel.: (+49 30) 20 93-46 746 (during office hours)
Tuesday: 14:30-15:30h phone hours
I hope that this helps for now. With any further questions regarding what exactly you applied for, please reach out to the Foreigners Office again and ask them about your application - or let a person from the study service help you out (to talk to them in German, for example).
All the best,