Shelly, this can be tricky and most of the time, once they are gone, they are gone :-( but you can try something. First off, stop using the DSi so that no more data is going to be overwritten. It is possible that those formatted files are still stored just invisible or inaccessible. The FAT or NFTS table erased the information about where that data was saved. The real data might still be intact intact in sectors. As long as that data is not overwritten by new data, it might be possible to recover them. In your case as with recovering photos from your DSI, I would try some photo recovery software. Get the free version and see if it can access your DSi. No guarantees, but nothing to lose. Hope this helps, good luck

Can your DSi be indetified as a hard drive by the computer without sd card? if it can, I think it is possible to recover data from it, try to connect the DSi to the computer without uplugging sd card, then down a recvoery software