Is my SD card corrupted?

I purchased an SD 4.0 GB card a few days ago and it came today. It is a Sandisk, the only model number on it or resembling that is three numbers/letters on the back, QC2. When I first put it in, I put it in the Samsung USB flash drive it came with and it read it. Before it would let me open the folder though, it said I had to format the card, so I clicked ok... Then I tried opening the folder to put some music on it, and it just wouldn't go on there. Then I tried taking it out and putting it
back in. When I looked again, it said that it's capacity was only
8 MB! And that's all it says, and whenever I try to format it again it's not letting me. It also says "memory card error" when I put it in my camera. This is truly frustrating and I hope to get some help on this issue...