Close Nedbank Students Account

I have had a Student account with Nedbank for 3 years now. Recently I have been receiving text messages on my phone that my account has been overdrawn, although there was still money (I haven't touched the account since December). I was never notified that my money disappeared from my account for no reason. Now that I decided to close my account, I have received horrible service. I went to the Vaal Mall branch twice, to be told they are closed (although I checked online and even phoned to confirm their operating hours). I even tried the online chat service to know how I can close my account only to receive no answer. It is getting very frustrating, as I have to take time off work to go close a bank account from a bank that is just *****ing money from me! I was under the impression that banking is an essential service during lock down, which apparently does not apply to Nedbank.