Went with this method (in AU and used UK store)

1. Went to www.game.co.uk and added a 60-day card to basket to be delivered online (i.e. emailed).
2. Paid with Australian credit card. No issues with international sales at all.
3. Receipt arrives in email five minutes later. Code arrives exactly thirty minutes later.
4. Entered into Mog Station, done. All working.

I also saved myself about $5 as opposed to the subscription.

This 401/601 business should have a fix within 60-days—you'd think—so until then, I'm playing.