Useless FNB staff that can't complete a simple task

I have been trying to close my account at FNB for over 3 months. I received an email at the beginning of June that they will close it, guess what, still not closed. I have followed up multiple times on this matter, with no response. Now the account is in minus due to account fees, which I will not cover. The last time I followed up, they sent me a KYC notice. Which I completed before they said they will close it in June. WHY CAN THEY JUST NOT CLOSE MY ACCOUNT!