Still no response from retention department for urgent upgrade

3rd attempt now to get my phones upgraded and still not a single call returned from Mtn as promised. I fly out the country soon and they just do not seem to understand the importance of my request I need it upgraded today or I want to cancel all off my contacts with Mtn and take out new contracts with Vodacom.they are just lying to me saying they will assist but they actually do not care for the customer at all really frustrating