Multichoice refuses to refund after debiting R350 more than they should have

Multichoice debited my account R350 more than they should have, i called them on the 2nd of Oct 2019 and have followed up 3 times since then and today when I called the person who answered the call told me that they have too many client to worry about my query and that they dont know if and when they will credit my account and refund the money to me. I asked to speak to the supervisor and held on for 36mins and Vusi (the operator ) kept telling me the supervisor (Vuvu) is to busy to speak to me . When I eventually asked for his name and the name of the supervisor Vusi told me that they are not allowed to give out there surnames. Which was so ironic as the first thing Vusi asked me when I called in was who did i speak to previously and I told him the supervisor Faiq and Vusi asked me what is his surname as they have many people with the same name. The service i am receiving is the worst I have ever had.