MTN 4G LTE network is already working in some locations and but before you can use mtn 4G LTE in your phone,
you must go and upgrade your sim in the nearest mtn outlet near you
Also your phone must support 4G LTE
network and also support mtn 4G LTE band !
here is a message I got from mtn
How To Get Free 5Gb From mtn In Your 4G LTE Sim
To get the Free 5Gb from MTN in your 4G LTE sim kindly send 4G to 131 ….
that’s all and you will be given the 5gb for free !!