Changing a 24 month contract to 36 without notific

I upgraded ( according the the consultant at the time) my contract to a higher amount. The consultant told me that there would be NO aditional charge because i upgrade. I signed ( and was explained to me by the consultant) that it is a standard 24 month contract. 24 Months later Vodacom informs me that i am currently on a 36 month contact! I have the following questions: 1: Where did i sign an addendumn to any 24 month contact that changes it to 36 months? 2: Why did the consultant not inform me that the contract would run for 36 months? 3: No person in their right mind would sign a 36 month cell phone contract? 4: Why did i have to pay R 5994.03 to have my contract cancelled if the handset was for free as the store manager explained to me? 5: If i had ( hypethetically speaking) another 12 months \loaded"onto my contract"