What is the meaning of start up data for MTN

This is the second time this is happening to me, I did an upgrade and did not received the start up data, the last time I had to log a complaint with the National Comsumer Commissioner to helped me, now again. I don't have time for this, all I want is the data that you promised or advertised, I was told by the consultant yesterday I will receive the data in 24hrs but nothing yet. I called the help line today and I was told 5-7 working days, what is the meaning of start up data then? Please help!!!