Brother is not taking care of my family after getting my father's job

My father was working as a lecturer in a government inter college .He died at the age of 59 just before his retirment.I was a final year B com student at that time. My Elder brother had appllied for a government job as an assistant teacher in place of my died father on compassionate grounds in a college after that my brother is neglecting me completely even after giving writen undertaking and application to take care of entire family he is not caring.what is the legal resource available as appointing authorties told cannot do anything once appointment is made your family matter.please suggest