Vodacom - Difficulty in Data Contract Cancellation

I have been trying to cancel a data contract since last week but Vodacom is not making it easy. Their call centre never picks up, cuts my call, does not call back and does not even have an email address on their website to address my cancellation letter too. Their reason for not having an email address on their customer care page is that they have a call centre number for speedy attention...This smells like unfair consumer practice to me. I will be making contact with the necessary people to investigate further.