Incorrect billing

I purchased monice data for R30 (2Gig)valid for 5days at around 19h00 and I was billed at 20h16 but with incorrect deal which is R47 (1Gig). I called immediately after being billed and I waited for 15mins on the line before I could be assisted, Then Mbali tried to assist & kept me on hold as she was asking if I could get refunded & told me they said its impossible to do so, and I demanded to speak to the supervisor , I was advised that is busy on the line they will call back after 30mins, even now I am still yet to recieve that call.. This error has never happened to me so it ****es me off to get such .

Nhlanhla Gumbi ***