I am due for an update and vodacom is saying I must pay for an additional 12 months

I took on a Vodacom contract on 29 May 2021. Today when i called customer care they say my contract is only due for an upgrade 01 May 2024. How come as its been 24 months now already. whats the extra 12 months for? I never too a new device anytime in between. Called cancelation department on *** on the 28 April 2023 at 13:58 spoke to Bradley Chinna who confirmed that there must be a system error. Vodacom should correct the Term Dates. Bradley Chinna also confirmed that my contract should have been due for an update from Jan 2023 already. It honestly doesn't make sense for me to pay for an extra 12 months on a cell phone that I finished paying months ago. My contract was taken on29 May 2021. Migration done on 12 Jan 2022 of plan to R245 airtime which moved my subscription from 199 to R245. I am due for an upgrade and vodacom should honor that. I have been loyal to them and haven't defaulted on any of my repayments for the entire 24 months.