CallBack / Please Call Me is a convenient service that allows you to request another number to call you back.
By dialling *121*number# you are able to notify the owner of that number that you would like them to call you back. They will receive an SMS from you requesting them to call you back. You will also receive an SMS confirming that your CallBack/Please Call Me request has been sent. MTN Swaziland customers are allowed to send a maximum of five CallBack/Please Call Me messages per day.