Vodacom is robbing me

For the past 3 months I have been getting ****** by vodacom,i have a 2 year contract with them of R370 a month,not even one year in to the contract and I'm being billed R1000 and more which is triple what I have to pay,they haven't rep**** any of my emails,iv posted on their page and they look straight past me like I don't have a contract with them,i want just to be served,i work hard for my money,not for ******* to take it and say they don't know what happened.