Not getting what is advertised

I upgraded my handset on the 26th August to the Samsung S8. with that I was to receive a 128mb memory card. I was told to log onto Samsung rewards, and select burn and then the product. There is no such product on the app. when I returned to the store the following week, I was promised that the manager would be in touch and follow up. today is the 19th September and I am yet to hear from anyone. I have tried to phone them a number of times and the phone rings unanswered. I logged a complaint on the mtn website and still had no feedback. I have been a customer for over 10 years and I think your service and follow ups are shocking. If you advertise a product then you should make sure it is available... if not you are lying cheating and *****ing from your customers.