Poor service from Vodacom renewal agent

I've just been contacted by a call centre agent in the upgrades department named Shaun. Shaun continuously kept on interrupting me, not giving me an opportunity to complete the explanation as to why I am not prepared to upgrade. Subsequently, Shaun refused to let me talk a supervisor and also did not want to share any means of me getting hold of a supervisor. I am disgusted by his attitude and his lack of empathy.