Vodacom wont allow me to cancel

I have been a loyal vodacom red customer for over 10 years and finally i decided i need a change due to poor service, I tried calling *** and follow the prompts to speak to a cancellation agent , the phone just rings for an extended period until i get asked if i want to be called back and then the line cuts off , i have tried this about 6 times and nobody answers the call, i then tried to select option 1 to speak to an upgrade agent and the phone gets answered immediately. this clearly shows that vodacom has no interest in assisting with contract cancellations. they lock you into one sided contracts and even when your contract expires they do not want to allow you to cancel.