unpleasant customer services

received email in May regarding errors of R4680 and today received email informing me that my account is on R7,132.16. Contacted the FNB call center and spoke with a rude consultant who keep on that she can't hear me & I sound like I am under water. She told me that I called and made arrangement of paying R8000. I am paying my account every month and don't understand about this errors and also who contacted me and requesting that recording