Account closure confirmed then not actioned now bank charges apply

I requested my Discovery bank account to be closed on 16 February and on 19 February a Discovery consultant called to confirm everything and I received an SMS confirming my account is locked as it will be closed.

On the 16th I indicated the amount of R83 left in account can be written off. I then received a SMS 9 March 2024 indicating I have an amount due and then noticed another month bank charges have been charged.

I made a call to the call centre and was told there was an amount outstanding. Firstly, i was NOT told of any amount or that an email with outstanding amount will be sent. Secondly, why as what must be done with my R83 if there was anything outstanding?