Charged for insurance despite crossing it out on contract

I upgraded my Vodacom contract in September at the Rosebank Zone shop. I noticed recently that the amount deducted is much more than I signed up for, so I checked it. Despite me crossing out the insurance part of the contract when I upgraded, Vodacom had signed me up for insurance with Cellsure without my permission, and have been adding this to my debit order since then. When I phoned to address this (Ref 1- ********** 245725), I was told that I had to contact Cellsure myself to cancel the insurance (despite me not being the person to sign up for it...!), and so I escalated it. A day later, I received an SMS from Vodacom, indicating that the complaint had been resolved, and that I had to contact Cellsure.

So Vodacom signed me up for insurance *******ly, and is refusing to fix their mistake.