If you do call, always answer "international" to the "international" or "domestic" question. This will avoid a telephonic stopover in India.

When it asks if you are making changes to your itinerary, say "no". The will dodge the international rate desk, which will not assist with your domestic seat assignments.

Evenually you will reach a live human in the U.S. who will not have slightest idea what itinerary you specified earlier in the call, so you get to start over from ground zero, but you will be able to have an intelligible conversation, and if he say's his name is Ralph, his name probably is Ralph.

Before you call, research available seating using the Ben Edelman link in themicah's immediately preceding post.