Calling up the social services is probably the best option - you'll have to man up in order to 'endure' all this crap though.
But if you just wanna be an evil cunt then by all means do it like this:
1) Get a group of your friends together (One must be able to drive)
2) You and friends sneak up behind father. Throw a bag over his head, tie him up and throw him in the trunk of your car or back of your van.
3) Take him somewhere a while away. Lock him in the shed or a basement, tie him to a stable chair. Leave all the lights off. Just have one bright lamp on his face.
4) With faces disguised, you and your mates carry out a little interrogation. Beat him up a bit, and round it off with threats that if they hear bad news about him again, it'll be the last of him.
5) Leave him alone for half an hour to weep.
6) Bag back on head, Father back in trunk, knock him out and leave him in hte middle of nowhere to work his own way home.
7) He returns home. Mom and sister know nothing, you apparently 'know nothing'. Father lives in fear. He's nice to you for a while. Can he charge you as a suspect? You're only 13, as if a kid could carry out an interrogation.
Now if he's still a bastard and you feel you HAVE to be a persistent cunt. Then resort to bringing in someone to do a little wet work.
That's all my advice for now.