I receved my usual monthly email: "Amazon Web Services Billing Statement Available / Relevé de facture Amazon Web Services disponible", which indicated that the payment would be processed in CAD, with an asteriks indicating: "* You have asked for this invoice to be processed in CAD. For more information visit https://aws.amazon.com/billing/faqs/#payment_currency"

When I log into my AWS account to change my default current back to USD, I am not able to. My only payment option in the dropdown list is CAD.