To get a refund for the Premium subscription purchased via iOS In-App Purchases or iTunes Store, you'll need to request a refund from Apple. To do it please follow the steps listed below:
1. Go to https://reportaproblem.apple.com/.
2. Sign in using your Apple ID. Apple ID should be the same one you used to purchase the Premium subscription:
3. Search for "IntelliVPN" and tap "Report a Problem" button next to subscription:
4. Select the appropriate item from the “Choose Problem” drop-down menu. In the text area, specify that you’d like a refund and describe the reason:
5. Then tap Submit button.
Also you can contact Apple’s team via Apple Support page.