Can't log in to Square Enix Store

I can log into the game fine, but not the store. I've made many purchases there in the past using my SqEx account. I tried changing my password and that didn't work. I tried creating a new account as I saw the message you changed the store - but it says my email address is registered. I don't want to lose access to my past rewards. Something seems broken. Please help.

Updating to add that I've already tried clearing cache / cookies, tried with multiple browsers, and 2 computers.

Good afternoon and thank you for posting on the Final Fantasy XIV Technical Support Forums.

Unfortunately, we cannot assist with Square Enix Online Store accounts over this forum. Please contact the Square Enix Support Center.

The Support Center can be contacted via the Square Enix Suport Website here: https://support.na.square-enix.com/

Please note live service is available Monday through Friday, 9:00 – 18:00, Pacific Time (Excluding holidays).

This thread will be moved to the 'Closed Concerns' subforum as it goes beyond the scope of this forum.

We hope we can be of assistance in helping you enjoy the exciting world of Final Fantasy XIV!