I guess there is a loop hole in Mtn server.
Try and see, you can confirm from the pics above.
You must have a balance of 20 naira or more on your account. U can do it 3 times and have 60gb. Dial
*298 * 2 * 2# , select xtradata and select 8, then follow d prompt.
To check your balance, dial *559*61#
Share to all your friends ASAP before it gets blocked
Comment below if you have any problem