Contract cancellation charges not compliant with a layman's view of CPA

I have a sim-only contract with Vodacom, on which I am paying R483 a month. The contract has 14 months to run, representing a potential future payment to Vodacom of R6672 (which obviously comes with a requirement for Vodacom to render services). I no longer need the contract, and asked for the cost of immediate cancellation, on which I have been quoted R7721. I'm rather sure this doesn't meet the CPA requirements of a "reasonable" cancellation, being greater than the sum of all future payments (and excluding any concept of the cost of rendering this service to me and/or representing simply the present value of the difference between what I am paying under the contract and what I would be paying outside of a contract).

On querying the above with vodacom customer-care, they have suggested I contact their cancellations department (who are the ones I'm complaining about :-)). Thus, next port of call here.