The first thing to do is to use the Albert E's guidance to cancel the renewal. You need to log-in on the My Details page, then scroll down. If by any means this procedure doesn't stop the charges from your credit card, then I recommend contacting the bank insurer of your credit card/account. They will block the payments automatically. Secondly, get in touch with the developers of the website and inform them you want to cancel the membership status and the automated charges.