Recover deleted contacts from iCloud backup:
1. Go to Settings > General > Storage and iCloud Usage > Manage Storage. You will now get a list of all available backups in iCloud. You cannot access a backup of a single file. You can either recover all or restore them all.
2. Once you find the iCloud backup you need, restore your iPhone to factory settings. But before that, make sure you have saved all your important files and data separately. Now go to General > Reset > Clear All Content and Settings.
3. The system will ask if you want to restore the iPhone from the old backup. Select "Yes" and then select the correct backup to restore.
Recover deleted contacts from iTunes backup:
1. Connect your iPhone to a synced computer using a USB cable. Once connected, iTunes will launch automatically.
2. In the upper left corner of the iTunes window, you will see a small iPhone icon. click it.
3. In the next window you will see a button called "Restore iPhone". Select this button.
4. Browse through all backups to determine which backup contains all the contacts you have lost. After finding it based on the timestamp, restore it.
5. A backup of this file will completely cover your current iPhone data.How to Recover Lost Contacts from iPhone 7/7 Plus without backup