Hi, This is probably too late but I really hope this can help you or others.
Firstly, We need to know why the deleted data can be recovered! When you delete a data, the phone mark the message as “deleted”. Actually it still exists on your phone. If the data did not be covered, then you can still get it back.
Secondly, The solutions to Recover deleted data are as followings:
1. The free solution is “recovering from your backups” . For iPhone users, you can recover through iTunes or iCloud backup. Of course, it bases on you have backups.
2. If you have no backups, you can try our ways.
For iPhone Users, you can use FoneDog - iOS Data Recovery. The Steps are:
Step 1: Connect your iPhone/iPad to a computer and install the recovery software
Step 2: Select the type of data you wish to recover
Step 3: Preview and recovery of data
Step 4: Choose what data you want recovered to your device