Subscription and payments are handled through Apple. Only Apple can process refunds for purchases made through an Apple iTunes account.
We also recommend that you cancel your subscription to prevent being charged again next cycle. To do so, please follow the instructions on Apple Website.
If you are facing difficulty in using or observing an issue, then please report the same with details. So we can provide support. Our engineering team is spread across geographies to keep the app and VPN services bug-free.