Vodacom greedy and disloyal

Vodacom is the greediest and most disloyal company that I know. I have been with them for more than 15 years and spent more than R500 000 on contract cost on them, but they still not prepared to discuss a way forward on a misunderstanding. I was contacted by a representative, this happens often, and asked if I would like to migrate two of my numbers to a better package. After listening to the rep I agreed on the migration but requested that she must e-mail me the details so that I can go through it on my own time. She confirmed to me that it will be done immediately (this was confirmed from the recording). I never received the e-mail and the migration was completed by the 1st of April. When I realized I never received the e-mail I had a look at the Vodacom App to see what the effect will be on my invoice. With shock I realized that there was a misunderstanding and phoned client service to stop the migration. They said that it will be done. Several days after this I checked again, and the migration was not stopped. I phoned again and the representative said he will escalate the issue. A manager phoned me and told me that the listened to the recording and I agreed on the migration. I explained to her that I think there was a misunderstanding, that I didn't want to pay more on my total invoice (I have 6 contract numbers with them). She said I will have to pay R4000 per number if I want to go back to the previous packages. On the question why I never received the e-mail to enable me to confirm that I am happy with the new packages, the answer was that the e-mail is system generated and she cannot take responsibility if it was not sent. My account is now R800 per month more and she said she can't and won't do anything else and I can take any steps that I want, it won't be changed. I will start moving my contracts to a different supplier as the come up for renewal.