Contract extended by 2 years

I upgraded my cellphone contract on the 30th June 2018 and it is a 24 months contract. And I went to one of vodacom store to check if I’m due for an upgrade 2 weeks ago. To my suprise my contract is only expiring in 2022. Which now makes it 48 months contract. I’m only due for an upgrade in 2021. I logged a service request 2 weeks ago and was promised that my request will be resolved within 48 hours. And till this date I haven’t received any feedback from Vodacom. And when I call Vodacom call center I keep on getting same feedback that my query has been escalated and will be resolved within 48 hours. According to me my contract is ending on the 30th June 2020..