Contract upgrades without my consent or permission 😡

I’m very upset 😡😡😡😡😡😡about your service the call centre agent is upgraded my contract without my consent or any agreement with me I found out after I visited the office around my town, I needed to cancel that upgraded contract this a full of sheet as much target are there this conflicts of interests from you guys the guy called me said is decreasing my payment and I asked he isn’t upgrading or extending he said no please assist me with the cancellation 😡