If you have deleted contacts from your phone by mistake, you can recover your deleted contacts by synchronizing them or restoring your mobile phone’s system.
How to Recover Deleted Contacts by Restoring Phone System
One way to restore deleted contacts is by using your phone’s restore system option. When selecting a date to which you will restore your phone’s system, choose one earlier than the day that your contacts were deleted.
How to Restore Deleted Contacts by Synchronizing (Syncing) Contacts
Another way to restore deleted contacts is by syncing your contacts. Start by locating your contacts on any email account that you have used to synchronize your phone with any service.
For example, Google’s app store, Google Play, offers backup information and contacts from your phone by keeping a copy of your mobile phone’s important information. To restore your contacts using Google Play, you simply need to select the Restore or Synchronize contacts with the phone from the email account option.