Billing: Poor feedback

<p>Cell C over billed me by R939.33. This is my summary of their response:</p> <p>We will credit you R891.22(?). May over charge R282.06. July overcharge R499.71. </p> <p>Cell will not bill me for end of July R99. They wanted to charge me R668.67 (?). And they have refunded me R222.55(?)</p> <p> </p> <p>Despite numerous requests to clarify the above, no-one comes back to me.</p> <p>Am I just thick, or does the above make sence to anyone? Their lack over feedback is really disapointnig. </p> <p> </p>