Vodacom charging me twice for service not received

Vodacom handed my account over to 2 legal companies after I have proof that they charged me for services not used. I was assisted by Vodacom after I queried very high bills, they confirmed that they charged me for data not used, and gave me credits. The charges however continued after investigation and when I refused to pay and wanted to stop my contract they handed me over. I e-mailed proof, affidavit and copy of ID to attorneys acting on Vodacom behalf...no joy. Today I agreed to pay the bill just to get rid of it on my ICT...now the attorneys want to charge me extra R1000 for their services. How did you service me???????!!!!!!!!!! I will be taking this matter further now.......enough is enough.....