How do you care for a Mother who you love but not like and who is mean to you at times?

It is total of six siblings in my family. There are four girls and I am the oldest girl. I moved almost 800 miles to help my youngest brother with my mother who is 81 years old because he asked me because none of the girls lived close to home Only my older and younger brother. I do not lived with them. Since I have been here my mother refused to let me help her with her laundry and it is piled up in a lots of garbage bags, cook for her or clean for her. I have spent so money paying utility bills and repairs. When I mention that I have paid something, she is quick to tell she does not know why because everything was being done before I moved back. The problem is my mother does not drive anymore and cannot get to the post office every week and check the mail. I have figured out when the bills are due myself and to keep from things being turned off, I pay them. The utility bills are in my mother's name and not my brother, My brother stated, he worked six days a week and it hard for him to get them paid. I spoke to my brother about my mother room (just full of all kinds of things/small amount of walking room) and nothing happen. I guess at times he doesn't want to say anything to her. When I spoke to my mother about her laundry and room, she told me I did not live there and she and my brother did. Also, my other siblings stated they couldn't deal with our mother. My mother attitude has only only gotten worst since getting older. Most of the siblings and myself have had our share of tears from her and God knows since moving back I have shed a lot more. But what can you do, that is my mother and she really needs my help.