Mobile plus and Mtn unableto corect mistake

Mobile plus has upgraded wrong contract cell number and i cant get hold of them. I still havent received the hand sets its now nearly 2 months, i cantget a sim swop of my main cell contact number wich i ask them to upgrade, yet no response or reply. Mtn store Glenn is also unable to help me do to my contact wich upgrade is still pending. mobile plus dont respont to emails or call back as i eplained via email the upgraded the cell number of my son who is residing in the USA so they are incompatend What can i do to get help in resoving this matter