Top up 100, not so much

At the end of Dec 2014 I went to the Rosebank mall MTN branch and was helped by Kiabetse Mogale (please mind the spelling if I got it wrong)<br> I wanted to upgrade and did so, to a Top up 100 and would be charged from Feb.<br> I have now realized that, after specifically telling her ,my airtime and data does not finish once I have used it up.<br> So I am being charged for the data and minutes I use after my allotted amount has been used.<br> <br> This is not what I wanted, this is not what I asked for. She in fact asked me on that day if I would be interested in this option and I very adamantly said NO thank you.<br> <br> Now I am expected to pay for something I did not want in the first place?<br> NO WAY.<br> I would like like the outstanding amount to be s****ped and to receive a refund<br> Not only am I upset that I did not get what I asked for but that I am now being debited for an amount I did not agree to. <br> MTN is therefore basically *****ing my money<br> <br> I have emailed a week ago, phoned 3 times, complained on Twitter with no help or response.I was told Kiabetse would contact me, nothing yet.