Overcharging (theft) and pathetic service

On 27 October 2015 I entered into an agreement to purchase a Huawei router on a R399 per month package. Included is 20 GB which was capped. On 1 November I received an invoice from Cell C where I was billed R1400 for the router instead of the agreed R399 and immediately attended at the V&A Waterfront branch in the first week of November to have it corrected before the debit order date (27 November). I was assisted by Naeem. After several attempts to get hold of Naeem (the consultant) who consistently promised to get back to me but never did and after almost daily calls to the call centre who eventually assured me that it will be corrected, the incorrect amount was deducted from my bank account on 27 November 2015. Due to the huge discrepancy, I elected to reverse the debit order until Cell C provides me with a correct statement of account. This whole experience was exacerbated by the pathetic service levels and unprofessionalism of Naeem and the call centre staff. By Cell C overcharging me even after they were timeously made aware of their mistake is tantamount to theft and a flagrant breach of contract. Shameful!!