A ********* ******* me to signing up for a phone contract

I have just got off from a call I received from the number ********** 248. The call agent told me he is calling from Vodacom because he can see on the system that my contract is coming to an end this month, which is true. I told him i want to cancel the contract, then he said i must give him the code he is sending to me if I wish to proceed with the cancellation, which I did. He asked me for my email address so he can send me proof of cancellation, when I opened my emails it said I had signed up for a contract with Vodacom where I will be debited R165 per month for a iPhone 6.