Misleading promotion - *****ing money

I have a Telkom DSL package for R499pm. On 15 Feb, a telkom agent phoned me to tell me they are upgrading me to Fibre, at no extra cost. She confirmed twice that I will pay the same amount as before. But after installation, my account was about R665. I phoned telkom to complain, and they lodged a dispute. A week later, they phoned me telling me that I must downgrade my services myself. I don't see why this is my problem, since I never requested the upgrade in the first place. I also have a recording of the initial phone call saying I will not pay more. If Telkom is not willing to give me what they offered for the same price, then I will have to discontinue my Telkom services. It is extremely disappointing and unacceptable that they are so dishonest