I know this is crazy, but I don't know who to ask/what to do!

So, we moved back in late July, and I obviously forgot to change my address everywhere. I did sign up for mail forwarding with USPS, but didn't even think about changing out my address in my online shopping accounts. I'm a dummy.

Anyway, I ordered a movie for LO for Christmas from the Disney Movie Club a few weeks ago. Today I realized we still hadn't gotten it. Checked, and yep, totally delivered to my old address. It was delivered on September 26th, so my assumption is that the new owners kept it. I know it's a federal offense to open another person's mail, so I'm not sure what I can do here. Is there any way to get it back?! Who should I contact?