ICICI Credit Card
Fradulent on line transaction

I have received an SMS this morning 5.56 am stating that a trasnaction of INR 1000.00 on 26.Feb 11 on my card xxxx7007 has been made at DUMMY ME ONLINE. As I remained at home yesterday and not use the card on the online purchase, I wonder how this transaction took place and what was the cause for it.