Never received my call back after complaint

I called yesterday to discuss a ridiculous account of over R2000 (they charge R2 a meg which is ridiculous) which my data had apparently run in to (I know of one download that did not complete that might have gone over but I have nothing to show for it). I sent all the required mails as they asked but still to receive the itemized billing which I again have to pay for (think they still have a few hours left to send it to me) but the call center agent was supposed to phone me back yesterday after 12 to discuss whether I want to switch to the top up package and she never did.