Wrong billing and threatening messages

Edgars Accounts dept keep on sending threatening sms messages about an overdue account that was paid on 30 October 2024. The total outstanding debt is R250 and R110 was paid - much more than the agreement. Complain at the shop was unsuccessful as the person (manager, I assume) said to ignore the messages. How can one ignore stupidity if a person who push the buttons keep on sending messages while I know the bad record will be posted against my account for THAT little money. I am afraid that this bad record will reflect on the ITC Transunion reports. I need a explanation as well as apology AND they must stop sending the irritating reminders and threatening messages without any reason to do so. And that for small money, R250 rand debt IN TOTAL. Can one believe it. No wonder Edgars shops face problems.