Tried again today. Another error 401. I guess I really am blocked for 30 full days. It might be less, but since I don't know how long the block will last (and neither does Square Enix, apparently), it's not worth trying before mid November because if I attempt it before the 30 days is up, they might just renew the block for another 30 days. Amazing!

Call me naive, but I would have guessed that "receiving money" would have been a little higher on their priority list.