Update

Two and a half hours after sending my e-mail, I got a call. The nice lady sounded as though she had a very large slice of clue cake.

She asked when I'd attended, then asked which campus I'd gone to, and suggested that I try to contact the College Park, MD campus.

Well damn, that would have been nice to know at the git-go.

She gave me a phone number with which to contact that campus. I'll try it tomorrow.

Meanwhile, I've gone to the UMCP/Testudo site and requested a PIN. If I can go that route, I may be able to avoid actually talking to anyone. Which would be, frankly, my preferred mode of dealing with bureaucracy.