That happened to me before, and I had to send an email to them asking to open a "research inquiry". They said they would and would send a letter if they found I was not eligible. So I waited a few weeks and the bonus finally posted!

I did wait 10 weeks before sending the email, so they wouldn't give hte standard response, please wait 6-10 weeks for miles to post. But I knew something was wrong since everyone reports receiving the bonus after the first statement.