Vodacom are *******

Hi my name is Ezra. I got a problem I have a R150 airtime contract with Vodacom to my understanding a R150 contract is R109 and up until now I haven't paid that amount the 1st month I paid R179 the 2nd R118 both months I query the problem after 24 hours I received a messege saying the problem us solved but it's not. This month I've received my invoice stating my bill is R901. I phoned them and ask them where does that amount comes from they said it's for a handset that was cancelled. The handset wasn't part of the deal I haven't received any handset so they cancelled something I didn't sign up for and now I have to pay the consequences and it's unfair because it wasn't what I signed up for. My contract suppose to be R150 for R109 without a handset. Please help!