Wrong contract upgrade

On the 28th of February 2018 I upgraded my contract on the ********** 712 to a special sim data only going @R379 for 60GB as Vodacom booklet says and fr the 1st till 2day I only got 30GB only and that is not what I wanted so where is the other 30GB . When I call the call centre they telling me the contract Is for 30GB only and am going to pay R367 exl. What the heck where did that deal come from I dont know but am sure as hell not going to pay for that.ID number ********** 467081.I will pay for 60GB R379.00 cause that is what am expecting and someone better fix this ASAP. Vodacom shop ****arney mall Johannesburg.