A man has been harring me for 10 years,was prosecuted years ago & was allowd take court for contact order?

He then abused our son as he did me,He gaind parental responsibility.withdrew his application as he would have got found out,now he's slandered me to social worker,she feels sorry for him,nobody believes me,now my son is on at risk register as they sat im mentally abusing him stopping c his dad.he has a new harrasment warning,but sits in these meetings being derogitory.social have disclosed our address.I am complaing officially,HOW CAN I GET RID OF HIM??Hes hurt me & son now