Vodacome contract upgrade

A guy from elite mobile called me to upgrade my Vodacom contract, he said since my contact term is about to end in May, Vodacom is giving me and option to upgrade my phone or data. I said I don’t want a new phone but I can upgrade data. He said it will cancel my remaining instalments and I’ll only be paying the new contract price for data. But that was a total lie and the amount that he said I’m going to pay is even more on my bill. I want to cancel the contact immediately. I’m not happy with it.