purchase the buyout tier in subscribestar hiding thread ask if you got questions along the way but it should be as simple as buying the buyout tier and waiting for eccma to send you a key and then unsubscribing from the buyout tier once the payments fully gone through
delete any cookies from a certain piracy site namely kemono.su(its former name you should know what its called now) and recreate subscribestar account since subscribestar looks for cookies from known pirate sites and makes your card decline if it sees them
failing that try selecting a different country after you add in card