HI Mohit,
IMO Low Level format leaves you little to nothing options for data recovery as it does zero filling of data. Still, you can give a shot at professional data recovery centers.
Before that, you may try various recovery software such as Restoration and File scavenger.
To prevent it from happening next time, i believe the better option is to try automatically saving/uploading your photos immediately in Picasa or cloud once clicking them. I'm not sure, but guess modern cameras' might offer such cloud storage feature in their camera settings.