Hi Bree!
If it is not in your inventory you are indeed out of luck but you can get it back! :-)
Find your kitty listed here:
http://kittycats.biz/pedigree/
Click the line with the specific cat you are looking for.
Then copy and past it's ID.
After that file a ticket here with it's ID mentioned:
http://kittycats.biz/support/index.php?_mo=vt
The kitty will soon be brought back to you by the KittyCatS staff.
Good luck!
Kay