How to approach bad communication with my department
If your department is like any other US math department I’m familiar with, it will have a graduate program coordinator (or similar title), a graduate program chair/graduate vice chair, and a department chair. The first two on this list will usually have office hours you can visit to talk to them about any issues you need help with. The department chair ought to be available to talk to you, either as a walk-in or by scheduling an appointment, if you have failed in your efforts to get one of the first two to listen. Through some combination of email, phone, showing up in person and knocking on doors, and gentle assertiveness, it is difficult for me to imagine that you will fail in getting someone to hear your concerns and work out a solution.

Good luck!