Security Breach - online purchase

Yesterday evening I got a notification of a suspicious online purchase on my credit card. I didn't get notification of the actual purchase. I didn't even get a notification to authorize the purchase whereas I usually am asked to authorize for smaller amounts. This was over R5000 with absolutely no notification, just a suspicion after the fact. I blocked my card and called the ***** division who opened the case. They said it will take 7 - 30 working days and I don't think that's an acceptable time-frame considering this is a breach with the FNB app. I have all my business with FNB but my online purchases can't be protected. The payment went off silently and I must wait this long. My salary gets paid this week. Is it even safe??? FNB allowed this purchase with no security measures in place. Now I am liable for this purchase, I will have to pay the interest on it as well. Maybe it's time to move all my business away from an unsafe bank. I need answers and a resolution now!!!