Open the Contacts app or People app
Check the Trash, Recently Deleted, or Bin folder
Restore the deleted contacts from there
Open your phone settings
Go to Accounts or Google
Select your account
Turn on Contacts sync
Tap Sync now
Visit contacts.google.com
Sign in with the same Google account
Open the Trash
Restore the contacts
Open iCloud.com
Sign in with your Apple ID
Go to Account Settings
Select Restore Contacts
Choose a restore archive
Confirm the restore
Check your SIM card contacts
Import contacts from SIM if needed
Restore from a phone backup
Use Google Drive, iCloud, or local backup
Reinstall the backup and sync contacts again
Open the Contacts app
Refresh the contact list
Restart the phone if contacts do not appear