Overcharged

I have been over charged for september and october. I have been paying R488 every month until now they charged me R582 of which I do not understand where it comes from. I called them on the 5th of September and was told it will ne escalated, nobody came back to me. On the 29th of september I called again and spoke with someone for over 40 minutes with my airtime and the person I spoke to promised me he was going to reverse the amount and I will pay the R488 I have been paying. On the 1st of October the amount debitted was R582 meaning it was not reversed.