Open the Settings app
Tap Phone
Tap Call Blocking & Identification
Review the list under Blocked Contacts
To unblock: swipe left on a blocked contact and tap Unblock, or tap the contact and select Unblock
To check for silently blocked calls: open Settings, tap Phone, then check options related to Silence Unknown Callers
If you want to review blocked messages: open Settings, tap Messages, then tap Blocked Contacts
Review the list under Blocked Contacts for blocked texts and calls