Discovery Card ***** from within!

On 22 October 2018 went into FNB (because my private banker ignored previous requests) and raised disputes over charges on my Discovery Card in September 2018. In November Discovery Card reversed the charges (subject to their investigation - no indication of how long this might take over and above the month that the complaint had already been sitting with them). on 23 January 2019 I called to confirm any outstanding transactions on my account and request the account be closed, on 25 January 2019 I received confirmation that the account would be closed and should there by any queries they would contact me. On 31 January I received an SMS that said accounts limit was exceeded by approx R 39 000.00 - bearing in mind that there was no further correspondence relating to the closure of my account from Discovery Card. 1 February 2019 the multiple daily calls from Card Collections starts on an account that was supposed to be closed. How is it possible that 2 months after you reverse disputed charges you can dip into a clients CLOSED account and hold them liable to repay the amount in full within less than 24 hours? You disgust me, that fact that there has already been ***** on my account and you treat me like a ******** and then proceed to behave like this?! I will NEVER do business with FNB or Discovery Card in the future.