I've had troubles with a couple of cards before appearing corrupt. This is how I fixed it (going from memory here, as I am at work).
On an Ubuntu box, put your card in, and pull up the "disks" utilities (how to get there varies on your Linux interface). Choose your SD card. Delete all the partitions that are on it. Format it as FAT, but don't choose the "quick" option, choose the one that writes all zeros to the drive.
Then, still on your Ubuntu box, use the utility called "etcher" I think (again, going from memory here) to write your Retropie image to the SD card. This utility is slower, but (in my experience) far more reliable than Win32DiskImager.
Last time I did this, the process took over two days. But, it did resurrect a 128GB card from the dead, which is working just fine in my friend's Retropie right now.
Hope this helps someone.