The battle of trying to sort out your billing!

I have a Telkom mobile contract and at the end of April I had issues with my debit orders. This put my account with Telkom mobile in arrears. To settle this I made an EFT payment to Telkom of R600 (my monthly payment) on 18 May, using the reference number on my statement. It was then supposed to be settled, and my debit order would just go off at the end of May, as per usual. Then on the morning of 26 May R1200 was debited from my account - which was supposed to be only R600. I immediately called customer service and explained the whole situation. The consultant told me that it is a case of my EFT payment not reflecting in time for the debit order amount to be changed. And that I would be refunded of my R600 in 2-3 hours. I then ended the call thinking 'okay, problem sorted' - the reference number for this call: ********** 6. And of course hours passed, no refund. Days passed, no refund. Weeks passed, no refund. Then I received my invoice for end of June payment on 9 June stating that I owe R2020,24. Like, how on earth is this even possible, if I am the one owed money??? I then go to the Canal Walk Telkom branch to speak to someone about this problem. They tell me, 'sorry, you can't sort out billing issues in store, you have to call customer service'. They even take down my details to give to customer service to call me the next day at 11am. Did I get a call? No I did not. So I called customer service, myself, on 22 June. (Nevermind the 15-20 min wait for a consultant, which takes airtime!). I once again, explain the whole situation to the lady on the phone. She made no effort to try and get to the bottom of the issue, instead only telling me what she sees on her PC monitor. She then gave me her email address ********** and told me to send the proof of payment of the EFT made on 18 May. I proceeded to email it to her, along with, yet again the entire explanation of the issue. And lo and behold, no response. A week passed and I emailed her again asking her for feedback, and yes, no response. Then I called customer service again this morning, and before I can even explain my query, the lady tells me, 'sorry, please call back in 2 hours time because we are doing system upgrades'. How is that professional? Why is it the customer's fault that you guys have upgrades to do? Make a plan that calls can still be fielded WHILE upgrades are being done. I also asked her if there is any store in Cape Town that I can go to where I can speak to someone in person about my issue, to which she had no answer! So, at this point, I REFUSE to pay my account until I speak to someone who is willing to assist me and sort out my billing. This is ridiculous man. It is my credit/payment record that suffers. This is not how to win over customers.