Very dissatisfied

I have a gold credit card with absa and i noticed on my statement an amount of over r500 was paid to an online overseas company which i had no dealings with and with no notification from absa whatsoever.I went to my nearest branch to query and a consultant told me to open a ***** case against the company which i did in the bank filling out the necessary documentation and i was told that the money would be refunded within 5 working days.I returned after 6 working days only to be told that there is nothing they can do and i wont get a refund instead they will issue me with a new card as if that will solve my problem.I am not a very happy customer because what prevents this from happening in the future again with the new card.