OK! I know this thread is very old. The starter must have restored his files back.
But, recently, I have this problem, too. Therefore, I just want to share my ideas with you.
Actually, there are several free recovery programs that can undo the formatting and retrieve your files back. But not all of them can be efficient.
Luckily, I have used
a reliable freeware, which has successfully restored my formatted data from my drive.
As to the recovery process, we also should pay attention something:
1. Stop using this drive right now to avoid overwriting the original data. Any new data on it may decrease the chances of successful data recovery.
2. Save your recovered files on a different storage device in case of recovery failure.
3. Always back up you data in the future.