Just because they say they're based in Illinois (or anywhere in the U.S.) doesn't mean they're actually IN Illinois (or anywhere in the U.S.).  They are based in Bengaluru area India.  Do a google search and you'll see a linkedin entry.  Also, we always check with each state's corporation listings to see who the actual contact person is -- it's amazing how many times it's someone in India.

This is why you're not getting a response.  Like so many other fly by night India-based companies, they close up shop, don't pay you, and then open as a new company listing.  What a racket.