last time i contacted SV about this, they said that if there is no “cancel subscription” button then you don't have an active subscription.
However i bought the supporter pack and am currently playing the game.
Im assuming that if the subscription isn't active then they cant renew the sub automatically. However i dont know for sure. My package sub ends in March, so ill see then what happens.
This is one other thing that SV gets an C- on. Its a damn, subscription game. Put a “start” and a “cancel” subscription buttons on the account. How friken hard is that?