MFC NEDBANK DON'T HONOR THEIR AGREEMENT AND PROMISES

In June 2022 I have made an arrangement with Nedbank MFC to freeze my account as per their advise as I am still on unpaid sick leave and they requested the documents which I have sent to them and I have called them twice to do the follow up and they confirmed it was done. At the end of the month they broke their promise and agreement and they debited my account which returned unpaid. When I call them and enquire about it they told me that there is nothing they can do and the account has accumulated the interests. They confirmed that they received my documents and they can see the arrangements but they can't do anything about it. This morning I sent them the email to make sure they don't repeat the same thing this month but they just ignored my email and sent me the letter of demand. Not even a friendly reminder but a threatening letter of demand. I will have to report them to the ombudsman because what they are doing is so wrong. I am a regular and good payer.