Construction problem

Asking for a friend .

My friend hired somebody that her sister knows to work on her basement. It’s a full basement but the thing is, it’s illegal. My friend didn’t get permits from her town to build the basement years ago so it’s illegal. She hired this guy to redo the kitchen and bathroom down there. She gave the kid her Home Depot charge card to buy the supplies needed for the kitchen and bathroom. He brought 1000s of thousands worth of things for himself. Before I continue, where I live it is legal to give a worker your card to buy supplies so that isn’t the issue. Anyways, he brought 1000s of things for himself plus 1000s of things needed for her bathroom and kitchen. Anything he needed for her house, he brought double the amount so he could keep all the extra stuff. The job is more than half way done. Only thing is the kitchen sink now. How she my friend go about this? She needs advice.