Insurance Department not helpful

I upgraded in January, received my phone all went well,however i asked that the insurance policy to be canceled that was in January, that was not done, i have been calling since January to date insurance policy is still not yet canceled. Each time i call customer care which is ***, they say they will call me back but the never do, i do not know what to do anymore as am being billed for something that i have requested to be canceled. All I need from vodacom is to cancel my insurance policy and refund me the money that they have been billing me for since.