Standard bank *****

Standard bank has always been good to me but I was disappointed. I have 2 complaints. 1st my credit card was ****** but it did not have money. To my surprise someone managed to buy things amounting to almost 4k with my card and my credit card had a negative amount. As that person was busy buying, standard bank called me to confirm if it was me buying I told them no and they blocked the card right away, which is excellent. Standard bank refused to pay that money. I did not take an overdraft with standard bank, how was my card able to buy things when it did not have money?Now I'm supposed to drown in debt and pay for the money I don know. Who activated the card to buy when it does not have money coz I never did. The person who stole my card was not supposed to be able to buy with my empty card. Please help.