i've been frauded

i got a call from my credit card company wanting to follow up on some recent purchases charged to my card. it was for a credit card that i used to use as my main card, but haven't used in probably the last half year or so. apparently this fraud called and had all my information switched (address, phone number, etc) and asked for a reissuing of cards to this new address. then started charging all over the place - some of the charges they asked me to confirm if i made or not were at some drug stores (didn't recognize the name), macys, target, etc. i logged online to the credit card (hadn't done so in a few months) and sure enough, there were a bunch of charges. this is the only card i have that i haven't been keeping tabs on - all other cards, including ones i don't use anymore are linked to my checking/savings account, which i check pretty often.

i've always been pretty careful about all my information, so i don't know how it happened. i'm obviously not liable for any of the purchases, and i'm not as concerned about that. what i'm really concerned is that this person has my security information because otherwise they would not have been able to call and change all the information to my account in the first place. so they for sure have my mother's maiden name. scary. i've never given that info out. i don't know what to do now to protect myself. anyone have any tips?

learn a lesson from me, check up on all your credit cards, especially ones you don't use. or close them. there's not a whole lot i could have done to prevent this, though - the person called just this past thursday to change all the info, and made all the charges after that. the credit card company caught it faster than i ever would have, so major props to them.