Why am I being charged double the amount this month instead of my regular rate?

Since you haven't given any real detail.. hopefully one of these two links will help.

you can view your subscriptions..

See or cancel your subscriptions - Apple Support

you can report an issue if you think there is one

Request a refund for apps or content that you bought from Apple - Apple Support

This is a user to user forum and Apple is not here. You can use the contact support link at the top of the page to contact Apple directly.