Im made to pay for the airtime I have not recived and I won't get the airtime either

In July this year I was called by an agent that convince me to take a contract for R70 a month and in return Vodacom was going to give me R110 airtime. I signed up for it as I was using more than R110 on airtime every month anyway. Today I called Vodacom to cancel this contract as I've heard it with Vodacom, it's just too expensive for my family, and the agent is telling me I have to pay R1300 to cancel the contract as this is a 24 months contract, so I must pay for the remaining 16 months. First of all I did not know that when I took this contract I will be charged for cancellation, I do not have any handsets from Vodacom. So I asked him if I pay this R1300 is Vodacom going to load that airtime of R1300 on my phone, and the agent is saying No. So Vodacom wants me to pay the R1300 for the remaining 16 months and they will pocket that money and they won't give me anything in return? How did you come to R1300? I did not take anything from Vodacom, why must I pay the R1300? I wonder how is this company still existing, the way they ***** from people is unbelievable! Can I get someone to assist to cancel this contract, my husband and kids contract, I do not want anything to do with Vodacom in my family. You are a disgrace! What does NCA say about this? make me pay and I get nothing in return? Does NCA allows you to charge for 16 months when the client has no handset and owes you nothing?