Refusal of my refund

Telkom did not debit my amount on due date. I called them to find out why, they then told me that my debi check mandate is not active and that I should make a cash payment. I made the cash payment and requested for them to send me a Debi check mandate. They send me a mandate that says R0.00. They then debit my account on the 25th of July. I call them requesting a refund, the first consultant tells me that he can the double payment and then he will put through the request for a refund. I then make a follow up call and I speak to Gontse. Gontse then tells me that the consultant failed to ask for my bank statement. I then send my bank statement to Gontse and email her asking for feedback, she ignores my email. I then speak to Phindile who then tells me that because it’s a new month I’m not liable for a refund. I advise her that I want my refund and she tells me that she can’t do anything. I find this very unexpectable as the error was on Telkom’s side!!! I want my money back