How can a case be filed against Bank of America for continuous Harassment, inflicted mental distress that caused my sister to go to the Emergency Dep?

My Sister's Mortgage home loan was with Countrywide until they were taken over by BOA. Payments were always made on time! They sent in our mortgage bill one month a offer to get a lower percent rate due to our excellent credit! They said pay these 6 months at this certain rate, and at the end of this time we will see if you qualify for the Home Mod. loan which would give you a lower percentage rate. She paid the 6 months, and waited. Heard nothing. Until she got a FORECLOSURE letter that stated IF SHE DID NOT PAY THE MONEY OWED OF $1700.00 that she was now behind, they would start foreclosure, and she would lose her home! She borrowed this money, paid it against her better judgement, and tried to explain what had been offered to her, but they wouldn't listen to her. Months of harassment, emotional distress inflicted for this mishap cost my sister her health, marriage, She ended up in the ED, was admitted,over medicated, forced shock treatments! She had no prior mental history!