Telkom Settlement Letter

So i went to a telkom branch in March 2019 to find out how much i needed to pay to settle my account. I was given the amount and told that i can only pay it at the Pick n Pay and not in store which is what I did. Now, August 2019 I find out that Telkom has blacklisted me for that transaction as there was R27 that was outstanding????? Why on earth would anyone short with R27 that you are not notified about??? Now I paid the R27 and telkom is not willing to send me a settlement letter. How do such companies still operate? Both the branch and contact centre cannot help. Closing down might be the best thing for Telkom.