Who is right? The customer or Vodacom??

Vodacom Greenstone upgraded my contract last year after having already renewed it in 2016. Yes still trying to work that one out myself! So knowing that i upgraded 2 years ago, i went in to get my new upgrade in May and was told "sorry your upgrade is only next year, being 2019". My daughter who is linked to my account upgraded her phone last year and so they just upgraded my whole contract. After a fight with them, i showed them my phone and in the properties it says 2016. Why would i be using an old phone if i had my upgrade?! They then agreed it was their mistake and they would get it rectified. 2 Weeks later and i am still waiting for it to be corrected. Every time i call i get the same excuse, they are waiting for the supervisor to amend it and of course you cannot get to anyone above store level! I find this totally unacceptable and wonder about their customer service! I am quite happy to take another phone now and upgrade again in a year's time. Nope cant be done because i need to wait 24 months, but they can upgrade my contract which was 12 months old! What do i do?