What can I do if my mother's home is in foreclosure and the lending company won't accept partial payments?

At the time my mother passed away, a person was allowed into her house. This person refused to leave and literally took over my mother's estate. The Sheriff refused to remove them since they immediately started receiving mail there. It became a "civil matter." Since we were not able to get in the house (we were told if we wouldn't stay with them we'd have to leave only with what we came with), we had no idea about her finances, who to contact, who to pay, nothing. It took me six months to have these people evicted. During that time, they used her card, cashed her check, allowed her car to be repossed, destroyed her home and literally stole every single thing out of the house. The Post Office would not stop the mail until I went through court for legal personal representation even though I am her only child. We are still trying to put pressure on the Sheriff to make it a criminal case since it was deemed "civil."In the meantime, the house has gone into foreclosure and the lending company says that since it is there, they are unwilling to accept any partial payments. It must be payment in full. Over 20k. I have agreed that I would be willing to work with the payments being made into the note, but, they won't budge. It is set for foreclosure in a couple of months and they are calling me all of the time to "see what I am going to do."From the moment I found out who they were, I immediately started trying to work with them. But, because I was not on the loan, they would not give me the information and I've been paid thousands of dollars in attorney's fees for eviction only to find out it is in foreclosure. Please give this family some direction. I never dreamed this was possible in this country.