I do not know Pandora and will have a look. Think it is not for OSX.
Prosoft's Data Rescue and Alsoft DiskWarrior are both very good and can be found free on "Grey sites".
I do not encourage or condone such things and pay stupid amounts for software, but merely state that they may be acquired.
With any such recovery program I find it best to run overnight as they take a huge amount of time.