Update: The activation of the free 120GB has been blocked after some users on Twitter reported to MTN. So, if you are part of those that activate the data before the blockage kindly make sure that you use it as fast as possible before they start wiping the data.
A new loophole on MTN data has just been discover. Over 120GB data can be activated on your MTN sim card without paying a dime. How?
How To Activate Free 120GB data from MTN
First of all, dial *131# then reply with 7, 5, 1, 1 and input your MTN number.
Or dial *131*7*5*1*1#
Now dial *131*4# to check your data balance.
Note: This loophole can be block at anytime. Use the free data while it last.