Threats and Duress

I have a gold cheque account. I have contacted the useless call centre to close the account on numerous occasions with empty promises that it will be done but nothing which has resulted in me having to pay, yet again, another monthly fee for an account that has not been used since October!!!!!!! I emailed *** to now be told that I need to go into a branch to close it???!!!! I went into a branch to be told they do not close accounts on weekends???? What utter bull is that??? FNB is ever ready to open accounts but *****s money when it comes to closing the account!!!! And in top of this, I now receive an in app message saying a Letter of Demand will be issued against me if I don't settle the account?! THE ACCOUNT IS SETTLED!!!!! IT HAS A ZERO BALANCE!!!!! THIS IS HARRASMENT AND DURESS!!!!! Close the account FNB and check your records before you harass people!!!! I will be taking action against FNB for the message I received!!!!