Vodacom gives loyal customers the middle finger :(

I have had my account with Vodacom for now over 20 years. A few months ago, I get a call from Customer service saying they have looked at my account and they can give me unlimited calls and double my data for R150 LESS a month, can they migrate my package ?. Well that's a no brainer...I verbally agreed and it was changed. Except my package wasn't R150 less, it was R500 MORE !!! I called customer service, asked them to explain. They said they would migrate me back to my old package... at the cost of R1000 !!! really ? you are making ME pay for your mistake? How about giving me the package you promised? I asked for a recording of the conversation where I agreed to R150 less not R500 more. I am still waiting. Several conversations later, they just don't listen. They now want me to a physically sign a contract agreeing to the R1000 migration fee. They were quite happy with verbal approval to migrate the last time. Sadly the only thing I will now sign with Vodacom is my CANCELLATION contract. Enough is enough. if that's how you treat your customers after 20 years, I don't want to be one of them