It would be backed up if you set up a backup or copied the email store manually, which does not look like was done. Contact the service provider, go to their web site or look at your bill for a number/email to get to them. They may be able to restore your contacts from their backup if they do that. If not, nothing else you can do except to try to re-create the lost info. You may have something in your emails with the contacts you are missing, sort by name and re-add them.