I scoured their web site and finally found a contact form. I sent in my request to cancel my subscription and left it at that. Well, looking at my bank account this month, I see I was charged $7 for their service. Curses. So I go back to the gmail account I used for this subscription (not wanting to get their sports-related spam, particularly non-baseball spam) and searched for a message from them. Yep, there was the email back from my form submission saying that in order to cancel my subscription, I needed to call their toll-free number.
Here's a tip for everyone running a business on the Internets: If I can sign up for something that lacks a material component (like a mailing list or a site membership), I want to be able to be able to deal with all aspects of that thing in the same place I signed up for it. So if I subscribed to your site using my browser, I expect to be able to unsubscribe with my browser. It's nice your call-center rep was able to pull up my account information and cancel for me, but I did not want to get her sales tactics (which were polite and all, but still unwelcome) to entice me to keep what I called to cancel.