A callback, or rather Please Call Me as it has come to be universally known in South Africa, is a rather nifty concept that allows you to send a free SMS to any other MTN customer asking them to call you back, usually because you don’t have any money on your phone – or are to cheap to use any of your own precious airtime!
MTN allows each customer two Please Call Me SMS messages per day, and to send is actually pretty simple.
All you have to do is dial *121*cellphone number# (where ‘cellphone number’ is the friend’s phone you want to contact) and a Please Call Me SMS will automatically be delivered to the relevant person at no cost to you.
Nifty.