What can i do before they return?

I was talking to someone i trusted about a situation that happened at home , Where i thought my dad was beating on his girlfriend but once i talked to him about it he said he wasn't hitting on her. Well the person i told repoted it and now the department of children services are in the situation they stopped by my house a while ago to talk to me and my dad i refused to talk , she asked for my dads number but i lied and said i didn't know it .I wasn't trying to get the department of children services in this mess , I don't even want them talking to my dad .What can i do to get rid of them but they talk to my dad ?