Nedbank is charging me still for a closed account!

I closed my account on the 22 January at the call centre with Shevon reference number ***. Today I get an sms telling me that account is overdrawn! I download the money app, and to my surprise Nedbank has now debited my account twice both January and February, even though there was no charges for closing the account. Let me inform you Nedbank, if that reflects on my credit record, because of your own stupidity, you will not only get a bad review. I am not liable for any cost on a closed account, especially the one's you are responsible for!!!!!!