FNB - How can we NOT help you?

I had a cheque acc with FNB prior to 2013, until I went under debt review. The account, which had a balance of R628, formed part of the debt review process and was paid off in 2014. Now that I want a paid up letter in 2021, they first told me that a letter will be sent to my email and gave me a reference nr. Then 2 days later when I made a follow-up, they say I owe them R 4000. I have been calling different numbers and gets send from post to pillar, back and forth. They keep putting me through to different departments. I have wasted so much airtime, and the issue is still not resolved. I don’t even know who to speak to anymore.