Horrible company to deal with

A while ago, my credit card was handed over. After making a few payments, I received SMS messages from Brooks & Luyt offering a discount if I set up a payment arrangement. I then called them and agreed to the arrangement, I have an email as proof. The agreement was for three monthly payments of R395.76.I honoured the payment arrangement by paying R500 on 7 October 2024, R500 on 28 October 2024, and the remaining R188 on 30 October 2024 (please see the attached proof of payments). The final payment was made following a call from Brooks & Luyt on 30 October 2024, during which I was informed that I had not honoured the agreement. However, after reviewing my account, they acknowledged the payment made on 28 October 2024. The representative then informed me that if I paid the remaining balance of R187, I would receive a paid-up letter from them.Since then, I have received numerous calls to both my phone and my husband's phone, with claims that I still owe the full amount, as they cannot find any record of the payment arrangement in their system. This situation is starting to feel like a ****. They sent me an email confirming the arrangement, but now they claim they cannot locate it in their system. What kind of **** are they running? They don't respond to emails, and when I call, I get no resolution, as they cannot find any record of the agreement. I kindly request your assistance in resolving this matter with Brooks & Luyt, as I have fully honoured the payment arrangement. I have made the necessary payments, and I should not be subjected to any further harassment or confusion regarding this issue. If this situation is not addressed, I will be forced to seek legal representation.