Unable to deliver on their promises

Vodacom keeps offering better incentives every time I try to cancel my contract - but they are unable to deliver on their promises. I'm not getting my data that was promised. I phoned in on 1 Apr: "It will be loaded within 1-2hrs". It wasn't done. Phoned 2 Apr: "It wasn't loaded for 24 months only 1 month. We'll escalate, it'll be done in 1-2 hrs". It wasn't done. Phoned 3 Apr: "We'll escalate, it'll take 24-48hrs". I'd like a manager to get involved and cancel this WITHOUT CHARGING ME A CANCELLATION FEE because Vodacom breached their end in that they cannot give me what I am paying for. Every month I have to phone in and spend 4-5 days on the phone because of some issue. Vodacom also still owes me a refund since January 2022 in that they deducted money for a phone that was out of contract already. 3 months later and I'm still waiting for the refund.