Inconsistant Turnaround Times for Refund 3 weeks

on the 20th of July I called the MTN 808 line after discovering that I have paid in about R3000-00 more for my MTN contracts. I was assisted by an agent who advised that the refund takes 24 hours to reflect in my account. so, on the 21st I called in to follow up on the refund and was advised that it takes up-to 3 working days for the refund to be processed, I demanded to speak to a supervisor (Portia) who then advised that the refund can only be processed after 5 working days I then demanded to speak to an operations manager or call centre manager whom I was advised \cannot take my call"they will \""relay a message for him to call me back\"""