If you are being harassed by someone through calls and texts, you can block them on your phones following these steps:
To block calls on Android, go to call history and click on the contact for a few seconds. Tap on the option “Add to Blacklist” and all the calls from that number will be rejected.
To block SMS’s on Android, go to the SMS list and click on the SMS you want to block for 2-3 seconds and you will see the block option on the top right corner of the screen. You will continue to receive messages from that number but won’t be notified anymore and the conversation will be archived.
With iOS, you can block contacts and phone numbers on your device. You can also filter iMessages from unknown senders and report iMessages that look like spam or junk. See here for further details on the same.