You can
recover deleted sms messages from iPhone, if you have made a backup before.
Here is the way you can follow:
1. Connect the iPhone to the computer with a USB cable.
2. Open iTunes.
3. If you have a new or erased iPhone, iTunes will prompt you to restore from backup.
4. Otherwise, Control-click on your iPhone under DEVICES in the left menu.
5. Select Restore From Backup...
6. Choose the backup you wish to sync and click the Restore button.
Learn more:
Tutorial 1:
retrieve deleted text messages on iPhone 5
Tutorial 2:
recover deleted text messages from iPhone 4S