I got hold of someone at Ontario Student Aid Programs this morning. It only took about 20 minutes on hold. The someone I got hold of was very nice and was able to answer my question almost immediately.
He was very apologetic when I reported my issue from the previous evening. He was even more apologetic when he found out that I had initiated my call at roughly 4:30 and had stayed on hold until after 6 pm.
Why? Because OSAP's phone service center stops answering phones at 4:30.
Is that fact stated on the automated attendant when it answers the phone? No, of course not, or we wouldn't be having this conversation. Yes, you read that right, I spent upwards of an hour on telephone hold on a line that no one was ever going to answer.
This is now firmly in the realm of bad_service. Fortunately, this is in aid of a student who's doing a Master's program, so I will hopefully only have to deal with these folks for 2 years.
[edited to fix spelling]
(Manitoba and Newfoundland both turned out to have much shorter wait times on their phone.)