[booboo773]

Go to Paypal, click on the Resolution Center link and Click on Report a Problem, click on Item Dispute and continue. Enter the Transaction ID on the next screen, or select it from the drop down menu. The next screen should give you the option of what was wrong, click I received my item, but it was different option. Select Different model, version, or size under the Materially different category and I would type a note to the seller informing him that you know that it is a hacked memory. I can't tell you what comes up next, because I can't go any further. (Don't want to accidently file a dispute against someone).

Whatever you do, do not let the seller convince you that you did something wrong by formatting. The only reason sellers don't want you to format is because you find out their scam. Do not ship the item back at your cost. You won't see your money or another player most likely. What I would do is find out how much 512mb players are going for and ask the difference refunded.