Charged for Internet Banking facility that I deactivated

I canceled my internet banking a long time ago. I have not logged in through their internet banking in a long time, as I now do not even have login details. When I looked at the statement I got after withdrawing some money from an ATM, I see that Nedbank has a deduction entry of R13.91 for Internet Banking. I can only assume that it has been deducted monthly even though I formally canceled that facility. Can someone please explain to me how this was reinstated, by whom and explain for how long I have been paying for a facility that I clearly do not use and I have cancelled a long time ago.