This was the message i got from them “Celebrate this December with FREE calls to family _& friends Receive 5 times what you spend every day as a bonus. Simply dial *507# to begin. Valid till 15-Dec”
So,if you are the type that love to make long calls then you should opt-in now because a total summary of this is;Load 100# get 500# free bonus to all network.
Meanwhile you can still get upto 3000# international call bonus all you need to do is to get a mtn sim that had been lying in your wallet for months then wake it back to life by loading 200# airtime on it.
Dail *123*1*5*1*3# to check your bonus.