Are you sure that is isn't in the Deleted Items folder anymore as a
subfolder?
You can try to restore your items by following a guide
which is on my site
www.sparnaaij.net in the How To
section.
When you haven't closed and opened Outlook in between
you'll have the best results. If you have restarted
Outlook in between the results are unpredictable.
If the items aren't restored at the first attempt you
could try again and delete more or other characters at
the beginning but I don't think it will work.
The best way is to install the pst back-up add-in from
Microsoft or download my script from the download
section; preventing is better the curing.
Hope this helps!