Pathetic Service

I have an airtime contract with Vodacom - which expires Sep '19. I called in to upgrade my phone on Monday - the phone I wanted was not in stock and delivery would take up o 6 weeks. I advised the consultant that i can not wait for 6 weeks, another cellphone provider has the phone. So i decided to cancel my contract with Vodacom and go with another provider. I called the cancellations department and was told that i cannot cancel my airtime contract since i will port the number to another provider. The Consultant advised me that i will be charged 75% of the remaining balance. My monthly instalment is R89, therefore my contract balance is R 1 068. 75% of the balance is R801. The consultant said my penalty will be R 1 087, which is way above the 75% and the contract value. I asked him to explain the breakdown and why the charge is over 75% - to my surprise, he said i don't know why the system just generates the contract. How *********** is that? I said, ok, can you transfer the airtime amount on my current number to another vodacom number thats listed on my contract so that i can just honor the contract rather than being penalised more than the contract value? The consultant said its not possible to transfer airtime. How is that not possible Vodacom??? Is that not theft?? Surely the number is on my contract and that shouldn't really be a problem. Can someone senior get back to me asap.