I'd suggest you, if possible,to first make a disk image and only then to try an recovery tool. This is to allow for multiple attempts without risking too much (you already did!).
I personally prefer to use
safecopy to create such a disk image. It's not slower than the usual
dd but it can also attempt for multiple strategies in case the disk has hardware failures. The disk image files will allow you different recovery attempts, even the more destructive ones.
Then, in cases like yours, I'd give
foremost a try as it can attempt for an automatic recovery of whatever is available on that disk image.
testdisk is also a good tool, though, but with different aims and features.
The fewer operation you performed on that disk after the format, the higher the chances you can recover almost every file.
I'd suggest you to follow
testdisk wiki to perform the recovery.