Double Deduction on account that can't be explained

<p>I noticed my December invoice was higher than it should be - upon inspection i realised there was a double deduction of the same amount: R298 excl VAT (R340 total) for 'handset installment'. I have contacted them four times now over the last three weeks and no-one can give me a reasonable explanation why there is a double deduction or when the error will be rectified. All I get is 'the accounts department is working on it'</p> <p>Worse is I notice that this is a trend that is being continued on my interim January invoice. :( </p> <p>PLEASE HELP!</p>