BAD BANK

I am sooo annoyed with Std Bank,Dec 2021 I asked them to close my account I paid every cent that I owed them.July/August 2022 money was mistakenly deposited on that account I had closed,they took all of it and started calling telling me that I owe them, my question is why did they not close that account? If I was owing them why for 6/7 months were they not calling me and collect their*money*.Can these people close this account because I am not going to pay them anymore cent of mine😡😡 These annoying calls are boring, from September/October 2022 they said they've opened an investigation on the matter but until today they have not come back with feedback of the investigation instead they're annoying me with collection calls still...