How do I cancel my Tera Club when playing on Steam?

I've searched for an answer beforehand in this forum but I only found explanations on how to cancel the subsciption through the launcher. I really dont want to download the launcher just to cancel this subscription. It cant be that people arent able to cancel the subscription when playing on steam. I've never seen an MMORPG where you cant cancel the subscription through the website. Its almost like you guys know there are a lot of people playing through steam and made it like this in the hopes somebody would give up trying to find a way to cancel the subscription. I bet it boils dont to me having to make a ticket in order to cancel my subscription