MP3 Corruption Fix

I was curious if anyone had any advice on how to reepair mp3’s that have somehow been corrupted.

I backed up all my mp3 files to DVD with DiscSafe. First, the files cant be opened or copied from the DVD. so I used CD recovery toolbox to restore the files back to my hard drive. Now when I try to open them from the hard drive, Media player says the format doesnt match the extension or it doesnt have the right codec to play. Any other player is similar outcome, file reads as 0:00 long and wont play.

I have used a few MP3 repair programs that I randomly found on thew internet but nothing has worked yet. Does anyone know what may have happened or how I can repair these?

Thanks for helping a rookie!