So I have not been on Subeta for a while. I didn't realize that I still had any form of subscription to the site until I checked my credit statement and saw a 30 dollar charge. At this point, I'm no longer interested in having a gold account. How do I cancel my subscription? For the life of me I cannot find any option to cancel it.

If no one is able to help here, then I'd definitely file a ticket.
https://subeta.net/tickets.php

I don't think you're able to cancel/remove your card until the gold account expires