CONTRACT TRAPS

I bought 3 telkom contracts a 2 smartplan 100 with 2 samsung s4 minis and a smartplan 150 with a s4,I specifically asked the people what will i be paying after the two years is done and i finished paying of the phone part.the answer was that nothing will change and u will just continue paying for the plan.so i woke up yesterday to find the the smartplan without the phone now costs R757 per month instead of the R100 i use to pay for it.to my surprise they reckon me that the data on these contracts was just a promotion and that i now have to pay extra .but when i purchased the smartplan 100 it never said that the data is only promotional and will fall away .they are a bunch of ****** .baai baai telkom ,and to think i promoted your service