Well, if you are looking to cancel your subscription early (before 6 months) this is "how you do it". You aren't supposed to be allowed to cancel before 6 months, of course. They will attempt to bill you 1x/week for three weeks. If the third billing fails they will cancel your subscription.

I've previously used my Wells Fargo Autograph (Visa) and my Cardless Avianca (Amex) cards with no issue.