Poor service from MTN Corporate

I took out a contract with MTN Corporate in Oct 2017 and my phone is still under warranty. I had a problem with the speaker and was told to go to a MTN outlet for them to assess and send for repairs in need. The people at the store 0127 was very friendly and gave me a number to contact after 21 days to track the progress of the phone. I was told that a replacement was authorised on 13/3/18. No one contacted me. On 20/3/18 to date, I'm, still unable to get answers fro Corporate as to when will I receive my replacement phone. Nobody knows what's the process for a replacement phone and the managers are not available. Still waiting patiently for staff like "Megan" and Mutle Mothe from Corporate to call me. Tebogo Mokgatlhe at store 0127 is a star!!!!.. Even though he could not assist e, he tried