Cancellation Incompetence

All I want to do is cancel my contract! On contacting cancellations they cant find my contract even though I give them the number and then give them an ID. Still no luck. In the meantime I have my account open on my computer, so its all there but somehow Vodacom cant find it. Then I give them the account number. Then put on hold ... Then told that Vodacom somehow used the account number as my ID number. How is that even possible. The length of an ID is completely different to an account number! Now I was told I must now go back to customer service so they can fix it, all the time wasting my time. Remember, I just want to cancel my contract. So they put me back to customer service and then go through endless menus to eventually just having a ringing sound and no answering. Mindboggling incompetence. How they function is a mystery to me.