How can YOU help me?

I had an account with FNB which has subsequently been closed. I went to the bank to open a new account into which I wanted my salary to be paid into and I was informed that I couldn't as my previous account had accumulated negative interest due to the bank charges. I have never received any communication from FNB to inform me that I owe them money and the charges have just been piling up. I have contacted their call center and have been sent from pillar to post as nobody knows which is the correct department that is able to help me. All I want to know is why were my \arrears"not communicated and if I had not gone into the bank"