Expected to pay a 36 months contract in 39 months without a valid reason from Vodacom!!!!!!

Am really disappointed with Vodacom, I did an early upgrade from a 24 month contract to a 36 months in October 2018 and I was advised that I need to pay the device on the old contract for the remainder, which I did with no Hussle, recently i was reviewing my finances and contracts only to find Vodacom system showing contract end date of Jan 2022, I called to query and tickets were opened and closed without my knowledge, I was advised to contact the Istore I took the contract at as they are the only ones who can correct the dates which I did and when the store manager called to query he was told that I need to call for them to resolve this as his not the customer which I did today and once again a ticket was opened, pending investigation and feedback from them.