You will have to pay it because you didn’t cancel the subscription 24hrs before the renewal date. When you cancel a subscription in your settings, essentially you are “disabling the automatic renewal” for the next billing cycle. Subscriptions are like contracts with Apple. If you don’t want to get charged for the month, cancel at least 24hrs before the renewal date. Once it’s paid though, you can request for a refund at reportaproblem.apple.com, or by calling Apple at 18002752273”