upgrade without my consent

Good day, I have been a loyal paying costumer to Vodacom for the past 2 years, on the 16th of pay I received a call from one of the consultants offering me an upgrade, I explained to her that I want to cancel the contract on the 31/9/20 as my contract is ending & I took those phones for my family members I am not currently using them. She then told me that since I do not want to upgrade for the next 5 months I will be paying for airtime only not the phone anymore as my contract will be ending, I told her its ok .I called last week to cancel my contract as I now that I must give 30 days notice , to my surprise I was told that I upgraded my contract without be knowing. I didn't not agree to an upgrade and I called Sibusiso on Friday & he then said he will give me feedback by Saturday I am still waiting . Today I called again the unknown lady gave me the number *** of which when I call it says its homemark of which they are not related to Vodacom. I tried my best to get this sorted but it seems like no one is willing to help me get this resolved.

Can somebody help