Suggest Treatment For Head Louse

i live in albany county and my 12 year old has had headlice for the last 3 months, we ve tried numerous times to get the headlice out and can t seem to get rid of them, i m now trying to seek help in which someone specializes in doing my childs hair so we can get rid of the headlice forever. any suggestions? don t know what to try anymore, feeling hopeless.