If you have never published your hub, then it should still be in your account. If it is not, then I would definitely send an email to the HubPages team about the problem so they can look into the matter. It won't retrieve your hub. That hub has gone bye-bye for good. Your only reason for contacting the team is an effort to make sure it doesn't happen again.
If your hub was previously published and then you unpublished it, then you are out of luck. After 24 hours, the hub is permanently deleted.
I am so sorry this happened. I wish I knew of a way to retrieve your hub. But, I don't think there is a way except to type in the title in the Google search tool and see if it is still indexed. If so, save it to your computer right away.