Ex and his wife are basically stealing my daughters clothes, shoes, toiletries and now a phone

My ex and have joint custody of our two daughters, Xo(12) & Yaya(11) the custody order is still new were 7 months in and on day 1 some mess happens. Leo and his wife are "struggling" but I'm always hearing about how much money they got for fun and habits.

He gets every weekend, each time they come back with just their phone and they are mad asf when they go back. The wife's sons have taken their things and won't give it back. One time they pulled up with the wife's two nieces one of them had on my daughter's entire dance outfit with her artwork and name all over it. Of course I said something this particular time was the only time I got an outfit back. Now my oldest daughter's iPhone has gone missing after a weekend with her dad she said it just went missing, I tracked it to the high school the wife's sons go to. I went to the school to see if they could help me get it back, the ended up calling the police to assist, they found it while the youngest boy was in class. He'd change everything around like it was his phone but he didn't update the account info. When they opened the phone my name and info popped right up. I filed a report my ex and his wife making excuses and are angry at me for being dramatic... what can I do in court? I'm going to petition in the morning I'm sick of these people!!!!

****I stopped sending them with clothes a month ago but Xo is insistent on taking her toiletries she takes her self-care very seriously she's just always on high alert over there. Now her dad is fussing about how I don't send what they need and he's "broke" but he wasn't singing this sad tune in court. He was a big baller then that can more than provide 😒