false contract advertising

I'm very upset with mtn on the 01 September 2015 I took a new cell phone contract the Samsung s6 for R499 I had waited along till the new month so I can get the new pricing so when I go to the mtn store I asked the guy when wil the price come down he said not any time soon. On the 4th of September the price came down to R479 pm and 1 gig of data free for 3 months. I am very upset I should be entitled to this deal as well I waited along time for the price drop and why should I miss out on a better deal which I was spose to be informed about because it's on the same month. The response from mtn has been ******* they just ignore everything I send them facebook messages emails nothing no response I'm so tired of been ignored by them.