Battle to close an account at EDGARS!!!!!

My mother (a pensioner), has paid the final amount outstanding on her account in August 2020 and asked the cashier to close the account as she can't afford any debt anymore. The cashier said she don't have to worry the account is settled. Now since then, she gets sms's and emails from Edgars accounts, saying she owe more money. We went to Edgars to solve the problem, they gave us an email address to stop the account, which we did. Still she gets sms that she owe them money and will be handed over. I called Edcon Head Office and spoke to Ronel at the Club Card, she gave me a reference number to confirm that she closed the account and I also spoke to Nandipa at the accounts department, who then said "the account has already been closed" and she will speak to her manager to reverse the said outstanding amount and send a confirmation to my email within 5 working days. Well it has been 10 days now and still no email to confirm. Instead my mom gets a sms everyday since my conversation with the accounts department, stating that she owe them money. Now who must I speak to now to resolve the problem to close the account please? The communication within the Edcon offices are a disgrace. Everytime I call them, (if they answer) I speak to a different person. Don't they actually make notes on the system while they speak to a person?