Thank you folks. I called in a few more times and "think" they were able to assign the requested seats. We will only know for sure at check in.

I asked them to put my United Mileage Plus as the frequent flyer number and they put in "Air India" in the frequent flyer program field, and my United Mileage Plus number in the frequent flyer number field.

I am thankful for my years of growing up in India that I am able to laugh at myself while calling them. I will try my luck again at the check in counter and "hopefully" they can update to reflect my United Mileage Plus number for the mileage accrual. Any advise is welcome.