"How can we help you" doesn't exist

I have had enough of FNB together with Groenewald Lubbe Inc. I am being harassed with calls, e-mails from Groenewald Lubbe Inc because according to them I am not paying my revolving loan account. I have been telling them that FNB debits my account every month for the same revolving loan. The last e-mail was a sec 129 letter. I contacted FNB and was sent from pillar to post, calls being dropped on my ear and Premier bankers kept being disconnected. Groenewald Lubbe Inc doesn't stop harassing me and FNB is not willing to assist. What must 1 do to get assistance?????