Worst service from fnb smart device

Good day I am an fnb smart device client, I recently received an SMS stating that my smart device is in arrears to which I immediately called fnb smart device centre and the call was answered by one lady named Maybelle matlekgale or something like that, to which she asked for my I'd number, cell no and add for verification which I gladly offered. The add which I gave she said it's not on the system which I then asked for other security question or we do the card an pin verification which she denaid and said she can't. So now I have to be blacklisted coz fnb is not willing to help me out. I want to them to deduct whatever is owed to them but the service I got is not in tune with the how can we help you brand. I'm so disappointed.