Hey
What you can try to do is going to Lc-Tech and download the Rescue Pro recovery software.
You might be able to retrive most of the data as long as you did not wipe the Flash Drive and had 0’s written on each sector.
Here is the link you can download the demo version for free and see if you can recover files. If it does you might want to purchase teh software or look for a different one. Rescue pro is a bit expensive but is great and does its job. Its easy to nvigate and understand.
http://www.lc-tech.com/software/rprodetail.html
Hope it helps.
BR