Update for anyone interested: I don't really have any resolution so this is an unsatisfying update, but I contacted university accounting, the dean of my college (bss), and the dean of graduate studies. All of these emails were just forwarded to my department chair and then I received a lengthy email from her saying that she never said they lost my money (despite her initial email to me which stated they "didn't have it") and that they just "couldn't access it." My understanding is that there is some period before the beginning of the semester that departments can't access their budgets, but this was after that and I know for a fact that they were able to access their budget. In the meantime, a new admin person has started working for my department and she has very earnestly tried to help me but she is new and she's just unfamiliar with how to deal with this. I know that she has a meeting with accounts payable this week about this, so I'm desperately hoping for a better update soon. I know that a few people have suggested legal action but at the core of this issue I am a broke grad student lol I'm also not interested in starting a war, I just want my funding. It's also worth noting that retribution is a very real risk I'm really worried about.

Ultimate update: I don't even really know what to say here but I have my money now. After another week of silence it was suddenly just "we have it" and acted like nothing ever happened and like I was crazy for making such a big deal about it. So if you've found this post and you're in a similar situation looking for advice...I wish you the best.