FNB Refusal to reverse

I made payment a payment into incorrect account numbers and spoke with the individuals who were meant to receive the payments, they said they had not received the payments. I phoned FNB to reverse the payments but they are telling me that they cannot do this. I really don'y feel safe anymore keeping my money in their bank because they do not care about my money. All they care about is the money they get from the fees they charge. So now strangers could be using my money because they say it takes 7 days to process this. My money could be gone by then!!!! This type of service is unacceptable!!!