Incorrect contract received

FNB offered me Cell C contract for R109 pm with 50MB, 50 min airtime, 50 SMS. I made clear only interested if current Vodacom nr be retained and I do not need more than 50MB pm and usually get by with R50 airtime with occasional top up. Was promised this will be still possible. Next day was called back and informed device out of stock would I be interested in next product for R169pm Samsung Galaxy Core dual. I agreed. Was not explained this contract for 25 min airtime an 1GB data!!! A vast difference to what I stated my needs are. This I found out later. Since I received the device on April 20th 2015 (which arrived without any documentation about the contract - only the Rica documentation, and the Vodacom nr not activated) I tried numerously to talk to someone at FNB and Cell C to assist me. I was sent back and forth with numerous people promising call back, send email to colleagues, escalate the problem, etc.. This far nobody seems willing to solve the problem. I used 084145 and 084140 with many extentions for some kind of service for past three plus weeks! Ref nrs *** and ***. I even received email bill for May ***. The attachment unopenable since .emc type