*****ulent transaction

I had an unauthorized purchase made with my virtual card for a store called Mac and things, i dont even know what that is. The purchase is for R988. What is most suspicious is that when I go to a list of transactions to dispute, it doesn't appear. Everything else does but not this one. And I always have to approve any online purchases, but I didn't get notification on this one. How can FNB allow that to happen? I want my money back and an explanation.