Account paid & closed

Good morning good people of SA Due to covid many of us have been retrenched n still unemployed. However I've made arrangements to make payments. Over 12 months I finally paid off my cheque account....through God's grace alone. Final payment was made end of November 2021, but yesterday I received a message from standard bank claiming I still owe R12914. 56..... Lol how does a whole bank not pick up that an account has been paid n closed. To top it off the contact info given goes to voice mail. But thanks to organizations as hellopeter we can report these issues