Savings not secure with you

Good day I logged on my account this morning as a regularly do to monitor unauthorized debits of R99.99 that have been going off my account over the years. I then phoned the number that appears on the transaction to know who they are & where they got that authority. The number belonged to Nedbank ***) & when I asked Nedbank who gave them authority they said I should ask FNB. I took my time & phoned FNB spoke to Puseletso who read disclaimer telling me that I should do cancellation in writing to the company that debits me, I then told her that Nedbank said I must ask you who is debiting me. Although the transaction was reversed I had many unanswered questions: 1. What proof do these companies give FNB before the authorize any debit? 2. Can anyone with my bank account give FNB an instruction to just do transfers? 3. Is my personal details save with FNB? 4. Does FNB really cares about its client or they colluding with this companies? 5. Is this an inside job? With those questions in my mind, Puseletso had a nerve to tell me that I am not the only one with that problem. Surely nothing is being done at the background to deal with this if staff confirms