After I posted what amounted to a "WTF?" post (I was not involved with this, but puzzled by what did happen...), I go on to BluGartr to see if they came up with anything.
Apparently, Square-Enix must've done a massive examination of their credit card files and basically LM-17'd everyone who either has had excessive charge-backs or the like...
I can understand having a policy in place if you believe that there is reason to believe that a monthly fee payment will be refused by the player's card's bank.
(I can also understand a lot of extra scrutiny when most of the players are effectively paying triple fees this month (Monthly, ACP, Security Token/Mog Satchel).
But an LM-17, especially with how that has been drawn as misconduct? (I guess you could say not having a valid card is misconduct, but...)
So that's why they are open extra time, to help players resolve this to get back in the game.
It sounds as if there has been significant credit-card related misconduct by players or others using unauthorized cards.
Sounds like Square-Enix has been getting bitten by quite a few chargebacks by people stealing others' credit cards or something -- heck, if they're stealing the gear from Square-Enix, why not just steal some poor schmuck's credit card and commit credit card fraud to be able to play??
But I reiterate what I said above: I think a different "code" needs to be made for that -- an LM-17 implies a misconduct ban. This should be closer to the non-payment codes or something.