“If you don’t cancel more than 24 hours before your renewal date, your subscription might renew.” [1]
Verify the status of your subscription(s), to see if they got canceled as you intended:
View, change, or cancel your subscriptions - Apple Support
Subscription that are canceled will be listed with an expiration date.
Ongoing subscriptions will be listed with a next billing date.
Cancel again, if the subscription is not yet set to expire.
Check your purchase history to verify that the charge is indeed this subscription fee.
See your purchase history in the App Store or iTunes Store - Apple Support
If you see 'itunes.com/bill' or an unfamiliar charge on your statement - Apple Support
Set your default payment method to ‘None’ without alternatives, to avoid unwanted charges.
Change, add, or remove Apple ID payment methods - Apple Support
If you can't remove your last payment method or use no payment method with your Apple ID - Apple Support