Closure of account

I have been calling telephonically and emailing Edgars at infinitum to please close my account. I never get a response. When I first started my account had a credit balance, i said non the less forget the credit and close account with immediate effect. Month after month they take off a service fee. Now i am in debit and to date my account has not been closed. Last call was on 19/10/2020 at 5.10pm where I spoke to Sibandile and I was told I would get a reply within 48-72 hours. To date 25/10 still nothing. How can I for once and for all close this account with immediate effect? Please help