Online & telephonic service non-existent

I am trying to get an upgrade phone on my contract, but I need to know which branches stock the phone I want. So I phoned a few branch numbers with no answer. I took to twitter and the respondent passed-the-buck to another account: @MTNzaService. I messaged them but received no response. So I ordered the phone online last week and was told that I would be phoned about my query, but I have not been contacted. I don't know how I'm supposed to find information from MTN.