I’m facing the same problem. If this isn’t resolved, I’ll have to post a negative review of the card on Amazon.
FYI, my card is the:
SanDisk Ultra 64GB MicroSDXC Class 10/UHS-1
http://amazon.com/gp/product/B009QZH6JS/
I’ve tried all the recommended format methods, can’t format/delete/write to this card from either Windows or Android. I even tried formatting via a camera, and it didn’t work.