horrible charges

My name is Itumeleng am a 27year old lady. Started using data not so long ago. To my surprise 100 mb last two days. I was told something might be wrong with my account because because if i go on the net it rip me off. I depend on my data to look for jobs online. I close applications after. Now I don't even visit the net anymore. Maybe like once anf for a min. Could it be that its Vodacom charges that Its this fast and so brutal or maybe my account. I spend time on whatzapp. People say probably my phone but how unfair is that. I need this explained and my data usage shown because I can't be recharging every two days just to be in whatzapp when my thing is to apply for jobs online. This is just me being **********. I asked around before I could contact you and everyone says maybe am on you tube but never ever. This us crazy.