False promises and refund not honoured - My money has been ******

In the beginning of December 2020, I called Supersonic for a relocation of my internet line. The was promptly dealt with and on the 15th of December my line was relocated. The billing from this point onwards has however been horrific. I was supposed to be charged the new rate for the 20mb uncapped line which was R845 per month as apposed to my old rate of R799 per month which I agreed. In Dec 2020 I was charged R799, in Jan 2021 I was charged R799 and in Feb I was charged R2107.39. I called Supersonic on the 1st of Feb 2021 when my DO went off to find our that I was erroneously charged. Supersonic have admitted that they made a mistake as they charged me for a pro rata rate for Dec 2020 on the new line + the full rate on my previous line + the full rate on my new line. Supersonic have acknowledged that I should have been changed a pro rata in Dec 2020 of (R799 / 31 days * 14 days) + (R845 / 31 days * 17 days), then R845 in Jan 2021 and R845 again in Feb 2021. I have called three times (ref CAS - 403766M0M2J0) and I have been spinned many stories and promises that my money will be refunded within 5 days (including other stories). Today is the 23rd of Feb 2021 and I still do not have my refund. Last week a gentleman by the name of Phillip contacted me from Supersonic and once again acknowledged the mistake, and said he will call me back within the day as he was going to handle the matter - well guess what I never received a call back and my refund is still not paid). I am once again shocked and disappointed by this service provider who think it is ok to get away with *****ing peoples money. Can someone please get back to me, sort this matter out and GIVE ME MY REFUND. THIS MONEY DOES NOT BELONG TO YOU!!!!!