Telkom messing up with client's credit scores

I initially had one contract with Telkom which my debit order went out on the 25th of each month. In December 2019 i took another cellphone contract for my daughter and i requested the lady that was assisting me to change the debit date to the 20th of each month. On the 26th of January 2020 i get a notification from my bank that there was a debit from Telkom and the bank did not allow it as i have changed my Telkom debit order date. I urgently called Telkom after receiving the notification to inform them, the consultant insisted that the money is reflecting on their side even after i had told her that the money did not leave my account. She then requested that i give it 48hrs and call back to check if it is still reflecting or not. On the 28th of January 2020 i phoned Telkom to check if the money is reflecting or not. The consultant i spoke to, told me that the money is no longer reflecting, i then requested the channels i can use to make a payment of which she did share with me. The very same day 28.01.2020 at 19:29:36 seconds pm i made a payment at Shoprite towards my Telkom account. At 19:35 pm i made a call to Telkom to inform them that i have made a payment and to also check if it is reflecting by them. The consultant told me that it was not refelecting at that very moment but i should not worry cause it will automatically be seen at Telkom and they will allocate it. On the 01st of February 2020 i get a notification from my bank that Telkom was trying to debit my account which led to my bank charging me R61 for an unpaid item cause i did not have enough funds to cover the amount that was being debited. I made a call immediately on the 01.02.2020, i spoke to Bonga who told me to send him an email and attach my proof of payment so he can escalate it to the refunds department of which i did. I called Telkom on the 08.02.2020 to check on the progress, two consultants hung up on me. Today the 14.02.2020 still no feedback from Bonga or Telkom for that matter. I then phoned Telkom again today 14.02.2020 for feedback, i spoke to Tsholo who told me that her Team Leader says Telkom will not refund me for the unpaid item that my bank charged because of Telkom. I requested her to put her Team Leader on the phone, she put me on hold for minutes and then hung up my phone. first of all, i don't understand how come Telkom debits my account after i have made a payment to them and engaged with them through out. whats even worse is that this unpaid item does not affect only financially but it also affects my credit score. Can i kindly get answers from Telkom, Please. If there is anyone who knows how i can settle my contacts, please advice as i have reached my max with Telkom. I no longer want anything to do with them. I don't believe that my first time of taking cellphone contracts will lead to such headache. No more cellphone contracts for me after Telkom.