Closing of Bank Account

I had have a Life Insurance policy with FNB. On the 16th of October I send an email to change with my new banking detail where the debit order should be deducted from. End of the month came and still FNB deducted the money from the old bank account where there weren`t sufficient fund. It was reversed as well as an amount of R 110 was deducted for Unpaid No Fund. I called 5 times during the 3rd and 4th November to correct this issue, as well as to close my bank account, but have been transferred every time to 3 or 4 different departments, I`ve even been put through to funeral cover. "Is it really that difficult to be put though to a department to close a bank account" I have been told I should go into the branch, however, I had COVID and have a medical doctor's letter. I want all my finds reversed and then closing my bank account