Mac and Things purchase on my FNB account

Mac and Things deduction on my FNB account. On the 10 February i noticed a purchase of R1024 that happened on the 07 February and unfortunately there was no money on the main account but still it went to minus even though I don’t even have an overdraft with FNB. What puzzled me was that the card used was the Virtual card that has already been cancelled so how did FNB approve such and even pay for that? CVV for Virtual Card changes every hour so how was it possible for a purchase to go through without notification?