Unhappy with Telkom service

I was on a sim only deal effective 01/02/2021 Smart broadband 90gigs anytime & 90 gigs night time. On 27/07/2021 I contacted Telkom as I saw an uncapped Smart broadband sim only deal for R749 I asked the lady wat is required to change from my current package to uncapped deal as we don't have fibre yet in our area. She confirmed nothing is required as I am a current Telkom client and I can switch to the which will be effective 01/08/2021. On 30/09/2021 an amount of R849 is debited from my bank account. I phoned on 01/10/2021 to enquire about the amount that was deducted and the lady confirmed that a once off R100 was added for activation, which I found strange as I have change between different smart broadband packages and never was I informed of activation fees. She also confirmed that with my new invoice only the R749 will reflect. I received my invoice 03/10/2021, my amount due is still R849, so the lady who assisted me on Friday did not know what she was talking about. I need someone to contact me ASAP as I need clarity on why I'm being charged more as what I signed up for.