sms retreival iPhone

When you sync it creates/updates a backup of your phone.  If the text messages were on your phone when you last synced you should be able to recover them by restoring your phone to that backup.  This will revert all data and setting to those contained the backup, not just messages.  If you want to do this:

 

Without connecting your phone, open iTunes on your computer and go to Preferences, on the Devices tab check "Prevent...from automatically syncing"Now connect your phone, right-click on the name of your phone when it appears in iTunes on the left sidebar and select Restore from Backup, choose your most recent backup to restore from.When complete, you can go back to iTunes>Preferences>Devices and re-enable automatic syncing.