Stop payment not stopped

I have a debit going off of my account which I stopped. The debit was due to go off today and as per the stop payment instruction it should have been stopped. The payment went off anyway and since I paid the supplier via EFT earlier in the month there were insufficient funds in my account to cover this debit. Now there is a R100 reversed item fee charged. I know the stop payment on the debit order was processed because I checked after I captured it, a few weeks ago and yesterday and this morning after the debit was reversed as unpaid instead of stopped. I completed a complaint form on internet banking this morning and no one has even acknowledged that my complaint has been received. <br> Please can someone investigate why the stop payment was not effective, ie why did the money still go off of my account. Also I would like the fee to be reversed as I put the stop payment in place last month already. My husband has the same issue with FNB allowing stopped debits to be processed. What a breakdown in otherwise amazing service. The supplier won't let me cancel the debit order, they said I had to stop it with my bank and now my bank lets them take the money anyway.