How do I stop any ociation with registertovote.org?

I gave the last four of my SSN and my cell phone number to registertovote.org. Then I noticed the fine print that suggested I was signing up for an ongoing charge of $9.99 (or some such amount) for I-don't-know-what. Is there anyway to retrieve my information OR stop the impending charge AND/OR cancel whatever "service" to which I have subscribed?