Mtn advertising deals that does not exist

I had to upgrade my contract with them and went to Mtn Mall of the South on Saturday and was assisted by Tshepo, we saw in the June booklet that they have the Samsung A20 for R249 for 1gig data and 100min. When we said that this deal as advertised in their June book is what we want... We were told that the price is incorrect! Really you advertised it at that price and that is the price I will pay, now all of a sudden we are messed around and given all nonsens stories with regard to this issue. If this is not resolved I will have to report this to the advertising ombudsman as this is false info.