Nedbank won't close my account

I am sick and tired of Nedbank. I've been wanting to cut all ties with them and close all accounts but they just refuse. Each time I've called them to ask to close the accounts, they either tell me that there is a movement on my accounts or I am on the negative balance and I need to correct. I need to call again the next day. It's been a month to be exact. I keep correcting these negative balances and paying them for nothing. This is exactly why I need this relationship to end! Cut it please.