If you no longer want to receive text messages or phone calls from a contact, you can block their number on your device. This however does not prevent the contact from leaving voicemails.
1.
From the Contacts app main screen, tap the Sidebar icon.
2.
Tap Settings.
3.
Tap Blocked numbers.
4.
Tap Add a number.
5.
Tap the Phone number field.
6.
Enter the number you'd like to block.
7.
Tap Block.
8.
To unblock a number, tap the X icon next to it.
9.
Tap Unblock.
10.
You've completed the steps!
