First National Bank Ignores Queries No Matter how desperate

I have had a banking query that has left me unable to pay rent, buy food, buy by chronic medication etc or look after my special needs child. It has been several days and my query has been ignored. I am stuck between a rock and a hard place now. I had to inform by son last night that there was no supper for the second night in a row. What type of banking institution can be so heartless? I have never defaulted and they have been paid timeously every month and I have been a client for 10 years! . What does FNB expect me to do now? I have lost all faith in them.