No service from Vodacom

I have sent emails and made phonecalls to cancel my cellphone insurance with Vodacom. With the emails the response I get is that my query has been moved to the TOBi channels and then I get no further communication or assistance. With the first phonecall I was told my request will be submitted, with my follow up phone call I was told it was cancelled on 7 Feb. When I called again after seeing the insurance still reflects on my bill I was told it doesn't show on the system that there was a request for cancelation. Then I had to hold on for another department to which I never got through and was told to call back later. I called again the next day just to hold on constantly and eventually gave up. I want my request to be finalized urgently and Vodacom must not dare to charge me for insurance again with my next bill.