Smh - I know how you feel because my package was also retuned - I can also relate to the confusion in this section too, it's funny because in this section I too left it blank, but when our package was return I checked it over again And we realized from this same section you are talking about I should be adding the contact information of the the representative , in our case I am the representative (sponor) and it's ok to be your sponsored person representative by indicating your sponsor's Mailing address and email in that section.
Thank God I did that ( because I kept reading the question over and over again) on the second submission of our return package that's when I made the revisions.
These forms are a headache and can be really confusing - i would think if your not using a representative i don't see why you can't put N/A .......like serious they should know there's not a representative being used in your application - you need to get this done and out ASAP like I did yesterday
Good luck and again I know exactly how you feel