Router deal

I received a call from mtn last week on a router deal package of which the amount payable was R290 for an unlimited data package as it was too good to be true i then asked if they are sure about this deal they assured me that it is a promotional deal hence they called , only to my knowledge it is a 100gb deal if depleted i will have to pay R1400 extra i did ask for a recording of the call upto this date no1 has came back to me