Wow, looks like they rumbled a big batch of people today
Only way of getting around it at the moment is paying for it via a foreign Apple account using foreign gift cards, and then paying for Youtube via your balance. That way Youtube has no payment information that they can go by. It's a bit of a pain but not the worst, happy to do it for the savings. I can't see them catching onto this too easily, they have no payment records to go by, and only the location of the IP using the account, which I don't think they could cancel Premium over without disrupting genuine people.