Please I need my contract to be canceled 1-

Good afternoon. I am soooo fed up with vodacom call center agents I've been calling for past 3 months for them to cancel my contract which I finished to pay on the 1 September 2020 instead they keep on upgrading my contract and I told them I want them to cancel it to prepaid coz I can not pay anymore bcoz I can't afford it but now they keep on dropping my phone calls,went to vodacom store crying out for help,they also dropping phone calls on their ears I am fed up I'm busy paying the money of the contract I've done to pay just now they upgraded it without my consent.