Woolworths Personal Loan keeps adding to the balance after I already paid the loan in full.

I had a Wooworths personal loan. I went under debt review in 2013 and they were added to it. The amount to be paid off as per the order was R17 427. The arrangement complete in 2019 and a total of R34 854 was paid to them. Yet I still get calls to pay an additional R1600. This was now handed over to the attorneys. I have my clearance letter already, but they still demanding money. I called in to ask for a detailed statement, but they cannot even provide that. Something is amiss, but nobody at woolworths can help! They keep escalating and I get no response. Are there any managers that can actually make decisions?? Or is this how Woolworths operate? Nobody takes responsibility to resolve the issue. Keep passing on with the same line, "I have escalated, and someone will get back to you in 14 days." All I want, is to get my paid up letter already. After I paid double my initial balance, I cannot believe they still want an additional R1600, which they cannot even explain how they came to that figure. I have paid the woolworths loan as per the court order. Please please please, give me a paid up letter and get someone to call me. I have made far too many calls, and sent too many emails, yet Woolworths wont take the time to understand and resolve the issue. Please help! Thanks! I'm not even sure why I'm writing this here... desperation I guess. I see they don't even respond to most reviews, so I can't even expect anything.