Does my ex’s family still have my mail?

My ex and his family are really shitty people. They are highly abusive. Literally down to his newly 18 year old sister. He’s used insiders to try to stop me from moving on, to get me alone, get information, and to continue the games he plays. His grandma tried to bully me into handing over my kids’ SSN. His brother locked my kids’ stuff up and they all thought it was funny. I got a PPO against my ex last month because he choked me with our two very young children (one being a 2 month old) right by us. Soon after, his grandma texted me a picture of mail that I had left by accident, asking for a forwarding address. I told her no and asked if I could pick it up, even saying I’d let them visit with the kids and then stopped talking about the mail, and told her I really needed that mail. They said they didn’t want to have to see me so they would only take them alone and stopped answering about my mail. Hah absolutely not. So I just didn’t answer. I remembered it yesterday because it had something I needed. So I messaged her and she claims they took it to the post office and said they had no address for me. But I changed my address with the post right after so I feel like they would’ve had that sent to me. She would’ve forwarded it a few days shy of a whole month now. My coworker told me they probably kept it or destroyed it and that’s why I don’t have it back.