Where is my money going?????????????????????????

I signed up for a contract for R399 per month. For the past 3 months I have been billed over R1000 for this contract and I have not even used this number since I have it. I have tried asking Vodacom consultants why am i paying so much, but nobody can assist me. I keep getting transferred to different department but the end result is always the same, NOTHING!!!!!!!!!!!!!!!!!! What on earth is going on with Vodacom and this poor service delivery???????????????????????