Vodacom robbing me

I have contracts with Vodacom just over R1500 a month and last month I was billed over R2100. Statement shows I'm being charged R599 for their fibre which I am not using. I called their store to query, they told me to call their billing department. Thereafter I was shoved from department to department without my issue being resolved. Vodacom are ******* *****ing from people. I'm trying to resolve the issue because I can't afford to pay R599 extra and the next payment will bounce because I'm living hand to mouth. And that is their own fault even if they take legal action against me the court will see I'm not earning much and I'm battling with Vodacom to solve the issue and they not helpful at all.