Visitor Visa - B2

My sis broke both herlegs in an accident and we are trying to get our mother here. I wrote to Chennai consulate stating the details, asking for a emergency date, but they refused saying they dont have dates! How can that be when the whole point of emergency is for unforseen circumstances ? So I asked them if my mother can go to Kolkatta where I saw dates in March, but Chennai hasnt replied and Kolkatta said no too. At this point I am lost. Has anyone faced this situation...i am desperately trying to write to all other consulates besides Chennai but no response. It is sad to note that even medical reasons dont seem to hold any priority and we dont even get an opportunity to present our case.