Default [Q] Erase data from bad microSD card?

Hi,

I have a 32GB microSD card that some how got corrupted transferring files between my Windows 7 PC and my Asus TF300 Android tablet. Fortunately, it is a SanDisk card and they are willing to replace it for me, but there was personal information on that card and I would rather they not try to recover the files on that card or even have access to them.

As far as I can tell, the on-board controller is bad, but all of the actual data is still just sitting there on the card. So far, I haven't been able to access the files or format the card with Windows, Linux, or Android, both in a microSD slot on a tablet/phone or in a card reader with an SD adapter. Most of the time, the device won't even recognize it as a valid SD card and when it does, I get an I/O error. Windows "Format" tells me that it has an "unknown size" and can't do anything with it.

Most of the information I have found tells me what to do with corrupt files, but not a corrupt card. Does anyone know of either a way to recover the card or any way to erase the data without having access to the card itself?

Thanks,
Don