Check the hidden Apps anyway.
Check on your computer.
Is it possible it was purchased with another Apple ID? My sons and I have separate ID's but share the iTunes library on the computer. Sometimes an App won't update on my device without the password from the user that purchased it....just a thought.
Other option: Restore from backup, maybe you can recover it that way.
(As SergZak mentioned...check the trash on your computer)
If it is no longer in the App store, you will not be able to purchase again.