earlier Scan lost

I formated by mistake a usb disk, and am trying to recover its structure with recuva.

I did a run with recuva, which showed 50 000 files and 58 Go needed to recoup it

My available space on the hard disk was smaller, so I could not use this result

Now, I have sufficient space, , but a recuva run shows only 500 files, those which were created by the formating

What went wrong ? How can I recover my 58 Go ?

Thanks for the help