Vodacom Early Upgrade Is A ****

I've finally reached my 21 months of my 24 months cellphone contract, I've been called today stating that I am due for upgrade. After almost completing the deal, I am told that I will have to pay for the 3 months that still remains as well as the new contract that I'm taking. What is the point of having early upgrade if you a charging me for two contracts. Utterly disappointed, if the problem cannot be rectified, I will most definitely be moving to another service provider.