I want to know why do apple company “ monthly “debit from my account a certain amount of money?????????

This is primarily a user-to-user support forum; other Apple users like you. We don't have access to information about charges to your account. See each of the steps in the following instructions. They include information on contacting Apple Support if the other steps don't help: If you see 'apple.com/bill' on your billing statement - Apple Support or go to Subscriptions and Billing - Official Apple Support

Also see: If you want to cancel a subscription from Apple - Apple Support