It should definitely be on that list if the playlist was created on the account you are logged into. Are you sure its definitely deleted and not hiding on your account somewhere?
If you can't find it get in touch with the Spotify support team directly using the online contact form and they can have a more detailed hunt for you.
If you get an automated email reply back directing you to the community or help pages, you need to reply directly to that email (even if its from no-reply) and one of the customer services agents will get back to you as soon as possible.
Alternatively, if you prefer support via Twitter, please tweet @SpotifyCares.