Still waiting for my MONEY!!!!

MTN was very fast to bill me extra however for the pass 2 weeks I'm still waiting for my money to be refunded. On the 2nd Dec I called 808, advised an agent Palesa Ngoepe that I was billed extra. She had a look at my invoice for Oct and Nov. She saw that MTN had not discounted my contract. She said the money will be in my account within 5 Days. 7 Days later I call 808, spoke to Prudence (Supervisor), she advised that Palesa did not request for the money to be refunded to my account and that she will do it and email me confirmation of the call. I haven't received the email and my money yet! MTN was very fast to debit my account, yet cant refund me on time.