upgrade of contract

i received a call from telkom around 22-25 Nov 2017 wanting to upgrade. i was sceptical and raised my concern with the current contract i had which was to expire in Feb. they sold me a deal that sounded like it suited my interest. i asked the lady to put a limit on my spend limit and advised that i call in once i received the device. my originall contract was R99 per month and the package is agreed to was R179. i was promised that i would be credited on my previous contract to the new one. i was also advised on a pro rate amount to be billed too. however now the statement comes and i am expected to pay R467.00. full amount of R80 charged and R0.50 amount charged on my account of sms that they said i sent messages. the worst is when i called in to set limit they advise it will be effective from the next month 1 January. i am told to monitor my calls and internet limit. they say sms will be sent once limit is exceeded. i have not received any sms but i am already on R0.50. This is the second time they made me sign a contract that according to the telecommunication of the contract it is not the same as explained. they dont give full informatiom and cant help customer avoid debt but instead want to put us in debt in the worst time. they have put a spend limit of R500 when i was on 0. Telkoms are theives