Being ****** by Vodacom

I took a 3 year contract with Vodacom for 303 rand per month it was an upgrade as my other contract was coming to an end,everymonth they charge me a different amount which is 359 or more per month this contract does not include insurance or any other benefits,I was also supposed to get 300 minutes and data every month they only give me 100 minutes and 1 gig data and free sms which was not included in this contract,I asked for the recorded voice call when I took the contract they said the matter is escalated to the manager who was supposed to get back to me in 2 weeks it was gone over a month I called again they said I will get a call in 3 days which nothing happened yet again,I really upset as I made it very clear when taking out the contract that I could not afford more than the 303 ,this the amount I agreed on and Vodacom is going to rob me for 3 years on the amount and the minutes as well.