R7000 bill for R75 per month data contract

I opened a data contract in August 2014 at Vodashop EL. This was a R75 per month 1Gig contract. Since August 2014 my monthly bill is R98.50 until October 2015 where i am advised it is an \open ended"contract and i have a bill of R7000.00 I try explain that the consultant who assisted NEVER indicated an open line. To open an OPEN ENDED data contract which is in a mobile ****le is pure recklessness and nonsensical. Unfortunately"