How to get back a deleted topic discussion?

I'm an admin of a group. Because of any reasons, I deleted a topic discussion in my group. Now, I want to get back that topic and the contain. Anyone can help me?
Thx before.

Hello,

Unfortunately it is not possible to retrieve the topic discussion, once it has been deleted.

Do you know the admin of facebook? Can I contact him, asking for him to retrieve the topic discussion. I hope the database not deleted yet from the server.
Thx 4 your answer...

Sorry, not possible. There's no contact method that I'm aware of.