Unfortunately many of the sellers are unaware what they are doing, buying cheap Chinese wholesale in good faith.
I was duped like this and my response was to start the site
http://memoracle.com which has links to free software to download which will check any type of flash memory card and if it is fake give you the proof to confront your vendor with, you will find they act very quickly in your favour with proof in front of their nose!!
There is plenty of information on there too and though it is aimed at SD cards, the software can be used with any type of card.
Good luck and I hope that helps!
