False Contract

I finished paying my contract of 24 months with Telkom on the 25/10/17, then mid November I received a call from this agent saying he's from Telkom and he would like to offer me an upgrade for R199 and he explained the benefits that come with that R199 that I will be receiving a Huawei P9+10gig of data every month+2 gig+ 1 gig free me +100 minutes+50 smses. Seeing that this was a bargain for me since I buy R200 of data every month I accepted it. I received the cellphone end of November 2017, and firstly it wasn't a P9, it was a P8 lite, then my bill for end December was R588, now my bill for January is R899, when I queried these bills on why they were so high I was told that I'm paying for the 10 gig that I'm using which I was told that it was FREE, also when I finished my 100 minutes the continue to charge me for the calls that I do since I don't even know when they are finished basically the automatically increase my spending limit without my approval or without me asking for it to be increased. The reason why I accepted this upgrade was because I was prepared to pay R200 or not more that R300, since its the amount that I afford, now Telkom **** to me and now they want me to pay for something that was falsely sold to me. I cannot afford these amounts and I'm not prepared to pay for such amount.