This happened to me too Vin a few weeks ago, but from PAYPA!L, so be very careful, I contacted pp and got it resolved and my $ back, took about a week though
mine was $100 five charges of $20 a piece.
I asked the wife (since she is the only one who uses itunes) if she made these purchases, because one I didn't think she had, she only purchases $1.99 songs here and there, never movies or anything and if she purchases more than one thing she gets an itunes card.....so i knew it wasn't here or certainly me.
pp took care of the problem and were very courteous about it.