Pushy salesman when i want to cancel contract

Due to Vodacom not informing me that my monthly bill will double after my 2 year contract period ends (and them not informing me that my contract is near end/ eligible for a upgrade) I have overpaid the last 3 months on my bill. <br> <br> I was informed by the branch that i should use the call centre service since it will results in speedier processing of my cancellation. Boy o boy, what a mistake. After waiting on the line for ages i was transferred 3 times where i had to wait on the line for ages again and again. Initially i wanted to complain, but quickly realised that nothing is going to happen because of it and that i will have to repeat myself every time i get transferred. Abandoning any hope of resolution i proceeded to try and get my contract cancelled. Every time i told the agent that i want to cancel he tried to sell me something different. This went on and on where i made it very clear to the agent repeatedly that i am not interested. After ignoring me 6+ times i started begging the guy that i do not want the products. Eventually i got helped. Now i am getting spammed every minute by +27 82 2716 with beeping on the other side of the line. What terrible service