Formatted iextreme usb - can I get the Sandisk files back?

Hi there, I had to use my USB quickly to fix my sons MacBook which has now been resolved.
It had to be formatted though and I’ve lost all my films etc which is fine.
I just want to get back on track and get all my Sandisk files back on it, so back to the original state similar to when when I originally bought it.
Anyone have any ideas?