LTE not working.

I did an upgrade with MTN to an Iphone 6 plus and got a SIM swap to activate LTE on the 1st of February 2015.<br> <br> Since then my phone has not connected to the MTN LTE network.<br> <br> I have called the call center and received numerous of refs, even been back to Mall@red shop with no feedback.<br> The normal feedback is .<br> <br> Switch of phone.<br> Remove SIM.<br> Switch on.<br> <br> I have done this now numerous times with no luck or feedback from MTN. The only info I do receive is that LTE is activated on my profile,well IT DOES NOT WORK!!!<br> <br> I have removed my SIM and tried it in another Iphone and it does not work!! When taking another LTE SIM and install this in my phone LTE does work.<br> <br> Can I please get a competent person to fix my issues, I am tired speaking to people that has a check/to do list, and when this does not work it gets escalated, escalated to whom as no one is getting back to me or fixing my LTE.