Hi, you can try do this:
- Download FExplorer
- Connect your phone to your PC
- Run FExplorer
- Browse your phone's directories
- Open the System folder
- Open Mail
- Find folders named 0010001_s etc.
- The files inside these folders contain deleted messages
Use FExplorer's in-built text viewer to view these files
Browse through the folders and open all files inside them until you get the required SMS