Vodacom Upgrade Department are ******

Was contacted by Vodacom Upgrade Departments. They said I was paying a said amount on my contract and because I have been a loyal account holder they want to reduce the amount I was paying. That should have already have raised alarm bells but I went with it. What happened is that the amount that they said my account was going to be reduced to is the amount I am currently paying , they just reduced it by R1. But now I have been bill with an admin fee 3x the amount of my monthly contract. I contact vodacom immediately but was told I can only dispute next month. I could not even file a complaint.