Can't Renew Subscription

[Mirakumi]

Keep getting this message:

An error has occurred.
Please confirm the status of any relevant options and then try again.
For details, please contact the Square Enix Support Center.
(Error code: 406)

However the Support Center is not working for live chat at the moment. Any advice otherwise would be greatly appreciated.

EDIT:
Chat live is supposed to be up; but it's unavailable now. ( 11:37 am est. )
It allows me to update payment but won't allow the charge process of auto renewal.