The official Square-Enix accounts site does not list any contact information without navigating through several redundant, automated help FAQs. Once you eventually find your way to contact information, it directs you to this forum.

I have several account/service inquiries to make, none of which will be listed here as a public forum is not a suitable location for such matters. I bought your game, and purchased a subscription, in good faith. I expect proper customer service.