FNB inept

On the 17th of September my husband and I went to our local branch to get settlement amounts on my revolving loan at fnb. We paid the settlement amount and now this morning I got a call from attorneys saying that I am R4600 still due. On phoning FNB customer care I was told that the info we received in the branch was incorrect even though while we sat there the consultant phoned the debt review department and got the settlement amounts. On asking the customer care consultant if I can speak to her supervisor she asked me Why, and proceeded in putting the phone down. This is not acceptable and I would like a resolution to this matter asap.