Unhappy client

I am not happy with the unresponsiveness from their billing department, I have been double billed for about R14 404, 69 for the current month whereas I have paid for the last month of October 2021, and I called their office and spoke to Zola and he told me that their records show that I have not paid for the month of October whereas I did, and the sad part is that I don’t get any response from their billing even when I call or send emails,