Cancelled contract was upgraded instead of cancelled...

Ive been trying to cancel a contract since middle of July when I was misled by a call agent, instead of cancelling my contract Vodacom upgraded my contract and 4 months later im still struggling to get it cancelled. I had to pay migration fees and was slapped with a bill R7800 for a contract i have which is only supposed to be R800 per month. the on going call logs and reference numbers are pathetic as each call centre agent has no clue what the previous agent has amended or requested on my account... Frustrated is not a word to describe the how i feel towards to the poor service from Vodacom...