Nedbank are pathetic and want money for nothing

I had a cheque account as well as credit card with Nedbank for many years, my mother opened the account when I was still very young. About 4 years ago I decided to switch over to fnb as their bank charges are significantly lower and the service I received from Nedbank was always bad. I didnt close the account with Nedbank as I still had my credit card with them. Last year I moved my credit card over to fnb as well as the interest rate they offered was much less then Nedbank. The last time a transaction of any kind happened on my Nedbank account was probably last year September, I think. There was still some money in the account. From Feb this year I started receiving threatening messages from Nedbank that my account is over drawn and I better pay immediately! I called and was advised that bank charges have now finished whatever money was in the account and I owe Nedbank R6!! I paid this immediately from my fnb app. The agent then said he cant close the account though as its above his limit.. I dont know what limit!! I must go into a branch to close the account. I havent had time to go to a branch so the messages continue and I now owe R20 something .. Please can someone just help me to close this account. I will pay you whatever is outstanding I just dont want to deal with Nedbank any longer.. I tell anyone and everyone I meet how moving to fnb was the best decision I ever made. Please, please, please Nedbank can this be resolved without me going to a branch.