Unhappy with billing of upgrade deals

Vodacom phoned me to upgrade my tablets. My contracts expired on 31 January 2020. I am very happy with my new devices, but received my bill, and my bill is doubled this month! I am charged for an upgrade admin fee, which I never with any of my upgrades paid before, except if I went to a vodacom shop. Now I am charged doubled for handsets as well on my bill, where they told me the costs will be exactly the same as my previous contract. I am not happy with this service, as they gave me absurd reasons for the double charge on my bill. So please, this is my first upgrade that I need to pay for admin fees, and my contract with them is since 2002, that is 18 years!