Nedbank (MFC)

In August last year I finished paying for the capital on my car finance with MFC through Nedbank. I was sent a form to fill so that I can refinance the ballon after sending it back they never deducted any money from my account. In february 2014 I got a call from lawyers and debt collectors saying that Nedbank have sent my account to them and they have noted that I am under debt review. I called MFC to enquire and was told that a lady named Thembi is the one handling my account and will be in touch with me. I have never received any call from Thembi, I have sent her an email requesting settlement amount on my ballon payment with no response from her. I need assistance because MFC have not been deducting any money from my account now I am just driving a car scared that it might be repossessed any time. I need Thembi or whoever from MFC to take this matter serious as it is affecting me negetively.