There's a lot of Counterfeit Sandisk Extreme III cards being sold on EBay recently.
if you bought one its 99% likely to be a fake.
it will be the correct capacity but be a cheap slow card, in counterfeit Sandisk stickers and packaging.
immediately demand all your money back from seller including shipping, and open a dispute with EBay and with PayPal. The Item is Not as Described. it is not a Sandisk product.
report the seller to EBay for listing counterfeit goods.
Leave strong negative feedback.
Escalate the dispute to ensure EBay bans them.
and PLEASE contact 10 other buyers who have bought these fake cards and alert them by copying this same message - if we all do this by spreading this alert virally, we can stop these crooked sellers from doing business again.