Vodacom forcing me to stay on a data contract I want to cancel

Vodacom is forcing me to stay on my data contract. I have asked them to cancel it and they simply ignore the request. Surely this is *******! They say you're supposed to get an sms and email confirming the cancellation and then you never get one. ******* company then has an excuse to force you to keep giving them money as they will NEVER send confirmation of a cancellation. I will have to take them to court to cancel this data contract!