WORST Service EVER - deducting money after cancellation

If i could give a no star rating I would, worst service delivery ever. When I bought my simcard in July 2020 I paid R 479 upfront and then again at the end of the month R 157 odd for Pro-rata usage. That means that when I pay at every end of the month I am still in credit for the next month. I cancelled my Rain March 2021 due to poor signal and no service delivery to fix the problem. There after they deducted another month of R 479?! Rain needs to referce the payment, this is *****ing. No one from service delivery cares about service delivery and only resonds after 3 days. Even when there were signal problem.