I can’t find my purchased movies

I purchased 4 movie through Xfinity since I’ve had this account. I had an issue with my Flex Box a few days ago where I couldn’t get it to turn on. Now it’s working, but I don’t have any of my purchased movies. The movies were 1. Seven Brides for Seven Brothers, 2. The Proposal, 3. Madea’s Class Reunion, and 4. The Year Without a Santa Clause. How can I find my movies? I was under the impression that no matter what, when you purchase a movie, it cannot be returned nor taken away.