Forced to stay with Vodacom when I want out!

On Saturday the 23 April I called Vodacom to find out how I must go about cancelling my contract with them. I was told I need to pay it up and it will be cancelled once I call the cancellation department. I done as I was told, but when I called the cancellation department on 28 April I was told another story. The consultant told me I must give 30 days notice if I want to cancel which the 1st person did not tell me. I'm extremely angry because I want to port my number to a different network and now I must wait a whole month. The consultant does not know how to do his job, he cannot handle angry clients he ended the call while I was still talking. He should have transferred me to a manager since he is ***********. I am disgusted with the service I have received. I do not want to be with Vodacom anymore let me go!