When you formatted the hard drive the question of whether you fast formatted or slow formatted is very important.
Fast formatting only deletes the drives dir structure and any decent recovery program can easily recreate it.
Slow formatting however changes every bit on the drive to a zero and therefore completely erases everything as it goes. Since you canceled the operated a lot of the data may be recoverable, it's hard to say how far it got before stopping.
Wish i was nearby to help you out.
