FNB incompetence

I had a business and personal account and credit card with fnb for the past 10 Years. 2 months ago I received a notification from the bank that my relationship was being terminated and I should stop using the accounts. I then settled all my outstanding payments and moved my funds to other banks. I unfortunately travelled before successfully moving money from the business account to settle the outstanding credit card balance that was due. I experienced a sim swap ***** while away and a ******* managed to buy things online using the said credit card. I returned and informed FNB consultants about this, I requested the balancs in the business account to be transferred to the credit card and received a reference number for the request of which nothing was effected. I keep receiving statements that I owe the bank and despite trying to sort this out I get slammed with very rude consultations who advise that once an account is closed the administration of opening it and transferring funds is next to impossible. For a bank their said size, this is grossly ***********