Bad to worse with Vodacom

This is not my first painful experience with Vodacom. I cancelled my cellphone insurance with Vodacom early this year and the consultant confirmed that it is cancelled and the next month I will not be billed. I have been billed for this insurance ever since that confirmation to date! I spoke to another consultant some time ealry in March. He said he will escalate the issue and someone will get back to me about it - none of that happened. I do not understand when Vodacom stopped caring about their clients so much. I have been with Vodacom for more than 15 years and as the years progress it seems as if service keeps going from bad to worse. I do not know what more to do for them to stop billing me for this insurance as now I am paying them and my new insurer at the same time because of this. I am truly lost for words...