Green Dot Debit Visa/Mastercard Deducted money for no reason at all Internet

I bought a Green Dot mastercard in September 2007. I recently put $56.00 on it on January 11th 2008. I went to the store on the 12th and spent $42.80 out of the $56.00 which left $13.20.

About 30 minutes later, I returned to the same store and made a purchase that totaled a little over $4.00. The cashier swiped the card but it wouldn't take it so the cashier decided to try a lower amount, which was $3.21, the card took that amount.

I got skeptical and started wondering what in the world could be wrong with the card. I went to the ATM and checked my balance after that transaction and the receipt showed that only $0.09 was left on the card.

I called the number on the back of the green dot card and asked for all of my transactions that took place, I was told that my beginning balance was 56.00 and I only spent 42.80 in one transaction and 3.21 in my last transaction and my balance was left at 0.09. Anyone can clearly add and see that my balance actually is supposed to be $9.99. I'm trying to figure out how they deducted 9.90. There isn't anything on the back of the card that says that they get a part of the money.

Sheronica
Starkville, Mississippi
U.S.A.