Unreliable Customer service

In December 2018 i changed my banking details at Telkom Cape Gate branch. My debit order with Telkom is on the 15th every month. On the 16 of January got a notification from my old banking institution that Telkom has debited that account in which there was no funds and was subsequently charged penalties. I immediately went to Telkom Centurion branch and was told that the person with whom i upgraded only loaded my new banking details and did not activate it as the new account from which debit order should be taken from. I asked if i could pay it manually and was told i can pay it at Pick and Pay and was given a printout to go pay there. I immediately paid it at Pick and Pay. On 4 February i received an email with my invoice which states i have to pay R202. 70 charged on 17 January 2019 as penalty for not paying my account which reads as a 'rejection notice' of which i paid that account on 16 January 2019. I have called customer service and had to explain my situation to a person who did not understand me and who asked me the same question repeatedly, i got so angry and told the person can i speak to someone else who will understand me as she was not helpful at all, the agent eventually hanged the phone up but was send a reference nr. This phonecall was the 5 February 2019. On the 8 February 2019 i went to the Telkom at Menlyn mall, my number was put in for a callback from the billing department, was told they would call in 5-10 minutes time, they never did. Decided to go back to Centurion mall Telkom on the 9 February 2019, same thing was put in for callback from billing department, today is 11 February 2019 and is still waiting for this callback. I feel so frustrated and angry for not being able to be helped from Telkom. The instore agents were friendly and helpful but your customer service over telephone pathetic and you as Telkom are ripping a loyal customer off for mistake made by you.