Terrible service

I am highly annoyed and frustrated. I called to close my bank account early in December. I contacted all my creditors to advise them of the changes. I am yet to receive confirmation of my request to close the account. This has now resulted in a creditor debiting this account which now had no funds as I was under the impression the account was closed. The account went into minus for this. It is now a new year and a new month and the account is still open. This has now resulted in me being charged another monthly bank fee when I asked to close the account early December. I am extremely upset as my account is now minus 888 and of course you will say I need to first cover the minus before the account can be closed!!!! This is your fault as FNB as I have requested to close the account which has not been done due to your pathetic service. I want this sorted ASAP this is unacceptable!!!!!!!!!!!!!