the NRMP website very clearly delineates that the only way to just match into a preliminary program is to put it on your primary rank list. the secondary or supplemental list does not get activated unless you actually match into an advanced program. the match algorithm runs through your entire primary list only. if you only list derm programs on your primary and don't match to one of them, you don't match an internship either no matter how many prelims you listed on a supplemental list. for this reason, people applying to very competitive things like derm, rads, rad onc etc often put a few prelims at the bottom of their primary list. this is discussed very thoroughly in many of the subspecialty forums.
i applied for radiology and was fortunate to match, but i chose not to put prelims on the bottom of my primary list because i didn't want to just match at a prelim as i was willing to do research for a year. however, i have friends who did not match rads, but listed a couple prelims at the very bottom of their primary list and managed to match into those internships.
from your previous posts it does not sound like the NRMP made a mistake or forgot to run your list. it sounds like there was a gap in your understanding of how the match actually works. the NRMP did not misguide you, the suggestions would be the same: list advanced derm positions on primary list, create supplemental lists for prelims. the what if i don't match a derm scenario should i list prelims at the bottom of my primary is not something the NRMP is going to go out of their way to suggest or tell you over the phone, but how it all works is described on the nrmp site.
im only saying this so you have a good understanding of how it works in case you have to do it again and for the benefit of others on this forum. as for now, i would suggest calling programs. i would also look into registering with various websites like:
Find A Resident:
http://www.aamc.org/students/findaresident/
Resident Swap:
http://www.residentswap.org/
just be on the look out and you'll find something. in the mean time, set up a research gig in case you don't find an internship.
think about it. the applications for next year are due in just about 5 months, thats it. how can you improve yourself in that time and during the next year, thats a question you need to ask and answer. im sure you will come across something very productive and if you stick to it you will make it so do not give up hope you just have to be very diligent now.