1. Go to PayPal and log in to your PayPal account.
2. Choose the Settings icon (next to "Log out").
3. Choose the "Payments" tab.
4. Under "Pre-approved payments", choose "Manage pre-approved payments".
5. Choose "KKBOX" and choose "Cancel".
6. Choose "Cancel Profile" to confirm your request.
7. Choose [Profile] to the top of the page

Alternatively, contact Customer Service through Online Customer Service → [Signing Up and Account] → [Canceling subscription] and Customer Service will notify you as soon as subscription has been cancelled.