They said i breached avo.
We said you are not allowed on property. Leave.
They said you are under arrest.
They started breaking door.
Door opened.
They grabbed me and then rammed my head into front of house.
1) Police have the right to enter your property in order to investigate/arrest a complaint or a person who they believe has committed an offense(breach of AVO is a criminal offense)
2) see 1 above .... No it's not the same as serving a warrant in case you're thinking of that precedent
3) For what?
4) Refusing to open a door so that an officer can carry out his duty is resisting
5) Do you have witnesses (apart from police), Dr's report of injury