Vodacom does not want to process my Contract Cancellation

I've been trying to cancel my contract with Vodacom, I've been calling them since last year to date they don' t assist. They have added a whatsapp monthly ticket and data deals that i did not request . I've been waiting for a cancellation sms since March when i call they advise they are busy with it instead they keep debiting my account even though i no longer want their services! Please assist how do I contact Ombudsmans for help