To deactivate Nomorobo Basic on your iPhone, simply delete the app. *This will remove the app from your phone, but will not automatically cancel the subscription.
To cancel your Nomorobo 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.