Citibank visa card
Wrong purchases shown

Hi,

I had a Citibank Visa Credit Card in 2005. I had hardly made any purchase. But one day I got a mail in my email account stating that I had made purchases worth Rs.16000/-. I had reverted to that mail requesting to send me the details of purchases made, but there was no response. Now the outstanding amount on the same card has outgrown to Rs.55000/- . I don't even remember the number of that card. But the bank is still sending me mails. How can I get out of this?