Well they certainly didn't need a lwayer, all they had to do was download the form off the IND site, fill it it, and send it off for the price of a stamp.
She is now an illegal immigrant and can technically be deported, but more chance of her winning the Lottery
.... she needs to discuss it with the IND on the phone, but as she has left it so late she probably will need to go back. If she'd done it herself, they more than likely would have just changed her visa status.
The solicitor can be reported and a claim made to get the money back.