Open the Phone app
Tap Recents
Look for the number in your call history
Open the Contacts app
Search the contact name or number
Go to Settings
Tap Phone
Tap Blocked Contacts
Review the blocked numbers list
Go to Settings
Tap Messages
Tap Blocked Contacts
Check blocked numbers there too
Go to Settings
Tap FaceTime
Tap Blocked Contacts
Check blocked FaceTime numbers
Open the contact card for a number
Scroll down to see if it is blocked
Use third-party caller ID apps if the number is not saved
Check voicemail for missed calls from blocked numbers
Ask your carrier for call logs if needed