APALLED with Vodacom *****ing money!!!

I was in USA for 2 years when I got back and viewed my online account with Absa I noticed that Vodacom was debiting me R129 per month for over 10 months for the time I was not here, I have laid a complaint and advised that I was not using the specified contract, Vodacom advised me that they would look into this, they opened up a case last year, advised me that they will do and investigation to see if the number in question was used and if the data was used, it is fairly close to 3 or 4 months and I have not yet received feedback, I think this is highly unacceptable, taking money from someone's account without any authorisation is *****, they have made no attempt to call me and refund this money, People work for their money not for companies like Vodacom to be *****ing it. This is such a huge and well known company, I can not understand how they could not get just 1 employee to work in this case and close it.