Vodacom *****ing my money

Was charged almost R1600 for data usage i was not informed about when taking out a contract. I took out a laptop contract with vodacom my installments is R469 and you get a wifi router and 1gig of data. Last month i was billed R2295 and got told this was due to out of bundle rates i have wifi at home and never even used the sim card supp**** by vodacom also the agent who did my application never explained to me anything aboug out the out of bundle rates or an open line if i knew i would have gone topup. I do not use the sim and an i am angered that i now received another bill for same amount. I need this rectified and my data usage which i was billed for to the amount of R1500 to be refunded to me immediatley.