Vodacom Contract Cancelation

Trying to end a contract with Vodacom, and I'm not able to take a call so I tried emailing them only to find out they no longer use that email, I tried messaging them on Facebook and the only reply I got is to call without any further help. I'm unemployed and can't pay my vodacom bill, I even tried to use the Tobi service to get in contact with an agent. Meanwhile the bill is kust stacking up, and no way to cancel my contract online.