Unsatisfactory experience with Cell C regarding outdated Contracts

I had x2 contracts with Cell C between 2017 - 2019. In November 2019 I called in at the Cell C Call Centre and asked to kindly cancel the contracts, I was advised to make full payments for both which I did. However only 1 paid up letter was supp**** to me. Fast forward to October 2021, My Credit score is low due to x2 unpaid Cell C Contracts dating back to 2019. I called in at the Cell C Customer last week to enquire and I was told that indeed the x2 accounts have been deactivated, I emailed and asked for the 2nd paid up letter and I have not received any response.