You can read further about the Apple auto debit with Touch 'n Go eWallet in the auto debit section within the User Terms and Conditions here
Below are the articles that may be useful for you :
What is Apple auto debit with Touch ‘n Go eWallet?
What is the wallet limit for Apple auto debit with Touch ‘n Go eWallet?
Can Touch ‘n Go eWallet be used for App Store and iTunes Store in other countries?