Extremely bad service from Vodacom.

I have been trying to cancel 2 data only additional contracts with Vodacom since January. It is an impossible task. You phone and they say they give it through only to see the debit order goes off once again. I have phone numerous times and sent a couple of emails to *** (apparently the only process you can escalate) It is almost R3500 that was ****** from me by Vodacom. I phoned today only to speak to an extremely *********** person who wanted to cancel my main contract and did not understand that I am trying to cancel an additional contract on my name. When I got frustrated she ended the call. What must I do to get any service from Vodacom.