Nedbank Credit Card

I had a Nedbank credit card a few years back. Due to financial situations I made a special arrangement with Nedbank. We had an arrangement to pay R830 for 60 months. Failing to do so, would result in the arrangement not being valid anymore. This was made clear in their letter dated 27 March 2014. I paid an amount of R 850 every month. We took out a loan in January 2016 and immediately phoned Nedbank to get the settlement amount on the credit card. My wife phoned them, as she had power of attorney on the account. This phone call was either the 25th or 26th of January 2016. After getting the settlement amount, she immediately made the payment and sent the e-mail to Nedank ********** We requested them to close the account and we cut up the credit card. All of a sudden, Nedbank started phoning us that we still owed them money. We requested them to send us the statements as to how they got to the amount as well as the phone call my wife had with them on 25/26 January 2016. They actually threw the phone down. Every single day they phoned us to know when we will pay, and we told them that we closed the account, we don't even have a credit card and that we want all the statements. It got so bad we told them that we are not willing to discuss this with them until we have received all the info and phone call as requested. Up to date we haven't received anything. Now they sent me an sms saying that a sheriff will deliver summons to either my house or work. As all phone calls are recorded, I have the right to request it. I want the phone call of 25 or 26 January 2016 and I want the statements and proof of purchases.