Thanks Cristián,
Unfortunately, I don’t think that’s my problem, but I think it did lead me to my problem.
So, for the first account I set up I had the problem above (probably something wrong in my setup that I’ve since corrected). For each subsequent account, the cancellation page showed up as normal and said it cancelled membership, but after that the same “Nothing to cancel. You have NO recurring fees.” error showed up.
Then it donned on one of my programmers: as far as S2 is concerned, they’ve paid through the end of the month, so it’s giving them membership through the end of the month and then they’ll convert to my basic Free Level after that. Is that correct? So far, in my searches, I cannot find any posts that indicate either way.