FNB virtual card *****

Be extremely careful of the new FNB Virtual card feature. I created my first virtual card a couple of months ago and I enjoyed using it till last month when R1550 was debited from my account via the virtual card without me even approving the transaction the way its suppose to happen . I assumed according to the advert that the CVV changes hourly this then can not be true coz how else would these people be debiting thr account. Ive made fnb aware of this as the money reversed 2 weeks later but I wanted them to investigate the matter. Being sent from one department to the next no one from fnb has come back to me to explain why people has access to my account of the card cvv is suppose to change and combat *****. This morning another amount went off of 14,99 from the same virtual card where the last. 4 numbers relate to the virtual card I canceled straight after tgat 1550 disappeared out of my account. So how can a card that is delinked from my account still somehow allow money to be deducted from my account. This is so concerning to me I work hard for ******** to just take my money the why it looks to me this is inside ***** happening. I hope now fnb will respond to me and not give me some **** of they looking into and the assure me that it won't happen again