What can I do if I have been advise that the child support I am paying is going to the parent's wants?

I have been told that the support I am paying is going to buy jewelry and body art for my ex. They were evicted from their house while I had the kids for a visit. But I paid support duting those months. She quit her job about a month after the kids came out to visit because of a personal issue. So she is unemployed living with friends. And I have to return the kids soon but don't think they are being properly care for. And my divorce is not even final yet