The files are not overwritten as a general rule. At least not all of them should be. Files are recorded on the card and given a name. Unless the file truly has been overwritten -- and that's not always the issue, you should be able to recover at least some of them. Before I'd surrender, I'd download the Lexar file recovery software (Image Rescue 4) and give it a try. I'm not saying it will do the job, but it has been a remarkable success for me. That's no criticism of SanDisk's software -- just my experience. BTW, I have gotten paid versionms of the software with Lexar-brand flash cards.