Misleading MTN

I currently have an MTN contract. I once called in to add on 10gigs data, which was put on and then I was advised of a deal that I qualified for which I was advised I needed to go to an MTN store to migrate to. I went to the store the following monday which I was then advised I couldn't get, I asked for a manager at Gateway shopping who was not even interested in what I had to say and also challenged what I was saying even going far as getting the consultant that had promised the deal on the line to tell me I won't be getting the deal. I then asked the manager to file an official complaint for me as I am not happy she promised to do so, but till the day I haven't heard from any MTN staff member.