Dissatisfied Customer - Contract Issues

I am completely unsatisfied with Vodacom’s service. I recently cancelled my contract with them, and the number was converted to prepaid. Despite this, I continue to receive invoices for the same contract that was supposed to be cancelled. This is unacceptable, especially since I explicitly requested that the number be cancelled completely as I no longer need it. To make matters worse, every attempt to resolve this issue through Vodacom’s customer care line has been a nightmare. The line hangs up before I can even speak to a consultant, leaving me with no way to address the ongoing billing problem.