Upgrade and unavailable stock

I would like to report dissatisfactory service received from MTN in Centurion Mall, close to Pick a Pay. I upgraded over the weekend and the salesman only told me that they do not have stock of the brand new iPhone after I have done all the paperwork. He promised that he will phone me back Monday to let me know if they are able to get a phone. I have tried to get hold of them since then and all the numbers I can find for them just keeps on ringing. Possible numbers I received from the Mall information center: ***, ***, ***, ***. What is the correct number?