Seeking suggestions on issues of domestic violence

Sir, my father SK. Jahangir Ahmed (aged 60) beats me and my mother regularly on petty issues and threatens either of killing us or throwing us out of our flat, while my mother has 50% share in the flat.The last incident was, he slapped my mother so hard that it caused her a black eye and punched me on my nose causing excessive bleeding.We had earlier lodged complaint in the local police station but they did not initiate any step.This time we issued a general diary and they said that my father will be called in the police station. They did not give any copy of the GD when we asked for it, only provided the GD number.Later I called in the police station and asked whether my father was called in the police station, the person on the other side furiously replied that he is not bound to tell me anything about what the police is doing regarding the diary. My quieries are: a) The offence for which we have lodged complaint, is it a cognizable offence? b) Do we have the right to know whether police is taking any step regarding the GD issued? If yes, then how to know about it? c) If we do not get cooperation from the police, what should we do? d) Can we lodge an FIR against my father? Thank You.