Unfortunately, Apple does not give developers any control over your subscription or billing, so we are unable to cancel for you. However, Apple makes it pretty easy to manage your Nomorobo subscription from your iPhone. To cancel your subscription, please follow these steps:
To cancel your Nomorobo Basic or Max subscription on an iPhone:
1. Open the Settings App.
2. Tap your name.
3. Tap Subscriptions.
4. Tap the subscription that you want to manage. In this case, Nomorobo.
6. Tap Cancel Subscription. If you don’t see Cancel, the subscription is already canceled and won't renew.
-For more information please check out Apple's Support Page by clicking HERE
Important: Uninstalling an app will not automatically stop your subscription. You must cancel your subscription to end your subscription. If you uninstall the app without canceling your subscription, you will still be charged.