Another guy in here said if you put mayo in their hair and run it through with a fine comb to take it out. That it would help. Wash their pillows and blankets, sweaters, anything that comes in contact with their head.

Once you use the shampoo without response try using tea tree oil or also what really works well for doing your own hair is good old mayonaise, don't laugh it really works well - just slather it on throughout your head and scalp then comb it with the fine steel comb through your hair rinsing the comb and drying/tapping the water out of it with each comb through.
The ridding process is long but it works very well.
You must do not only your head but you must wash all bedding, any areas of furniture that you lay your heads, the back rest of your cars, basically any where you place your head but also any combs, brushes, hair rollers, curling irons, barrets, hair elastics etc...It's not a nice thing to get head lice and harder to get rid of. But once you have the routine down it becomes a science to rid yourself of these pesky things.

Good luck, I help my girlfriend with her kids all the time.

Ive tried everything and im getting desperate.I might try my cats flea control called advantage.