Horrible Experience Vodacom Contract

I am havinf a horrible experience with Vodacom, I did an uprade in December 2022 for a 24 months contract, I was told my the crontract I had back then was due to end in April 2023 so I will be paying an extra amount until April 2023 to finish the old contract. I did that and in May I was then paying the normal contract fee amount, in the new contract I was given a sim card that I noted that is also on contract for 24 months and that was not explained to me. This year I was checking when is my contract end date coming, I was told that the extra sim card that I was given it will end in December while the other original number will end in April, if I ask them that how come is that since it's one contract signed on the same day, I was told that it is because I did an early uprade. I explained that I paid for old Device until it's end date of April and also that would mean the contract is now 28 months, they just say that's how it works, what shocks me is that all the people I speak with they all see that the is an error and they will escalate it and after that I do not get response the only time I got response the lady said that how vodacom works, I asked to be put through complaints and no one contacted me. So I am really disappointed with such a service and this is a second time that vodacom does this on me.