Okay, so I wanted to pop in here to CONFIRM that this works.

Also, please understand something: The woman at Ultimate Pay told me why this is happening! Square-Enix has a safeguard in place so that large transactions on brand new accounts are restricted. So, everyone trying to buy the $77.94 amount, was being declined for their own safety since it is a new account without a transaction history. You are being locked out entirely after too many failed attempts (which is also what displays in the 601 error message.)

She basically went in and manually added the funds from the Ultimate Pay Game card since my account was locked out entirely and restricted from too many failed attempts!

This is not Square-Enix trying to piss you off, it is simply due to a safety precaution (and possibly a little too much oversight, since they should have known people would try to purchase 180 days out the door!)

I hope this makes everyone a little less grumpy and a little more able to play!

Purchase your Ultimate Game Card from their website, or from Walmart's website (as OP says in first post) and follow OP's instructions in getting declined once, and calling the number. You will be able to play! I promise!