Xbox Live XBOX LIVE unaurthorized use of credit card redmond, Washington

contacted xbox live this summer to let them know to cancel the acct the following month of September, remove all credit info.  The end of september my bank notified me of a charge from the xbox live for 43.24, I was furious since they were not authorized to use my card or even keep it on file, i immediately called the same night of the charge to find out what it was for, they claimed there was a purchase for a game through the console, funny thing is my son was NOT home and me nor my husband play this thing at all.  I told them it had to be wrong yet they insisted it was done not believing me, so after i cursed out the customer service rep and insisted on a supervisor i told them i want a refund, this charge was fraudulent and erroroneous. 

In the meantime my son came home and I had him log into the console to see if the game they claim was purchased was in there and behold it was not and i relayed this to the supervisor, i told them i will dispute this charge as a fraud to my bank as well.  Then they told me it would be 21 business days for them to investigate, i told them maybe if they did their investigating before charging peoples accounts this would not be an issue. I told them if they EVER charge my credit card again for anything im sueing their asses, remove all my credit info from my account immedately as they were instructed to do almost 2 months before this happened. The principle is not the amount of money they took but that they just take money without authorization, im getting my money back one way or another.