First off - BACK UP YOUR DATABASE, before even reading the rest of
this message!
If you have Compacted and Repaired since the mistake, you're out of
luck: that data is gone forever. (Well, maybe some of the wizards at
the NSA could recover the data from your hard disk but they don't work
on contract for the public).
If you haven't, then contact Peter Miller at http://www.pksolutions.com for his highly-recommended database salvage
service. Have your credit card ready; it's a reasonable cost though
and he doesn't charge if he's unable to recover your data.