Once something like this happened with one of my friend. One of her fans asked a custom long video where she have to say his name during the videos. My friend agreed to her for $100 per video. After 2 days when she send her video with a message that your video is ready then the other person is not responding to her. Then after that that user didn’t replied to her. Through she used the videos for some other purpose after editing but it was complete waste of time for her.
Many creator face this issue that user is not paying for the custom video because if user is asking for video then it depends on him whether he will pay for it or not.
For safety, you must send the video in locked messages so that user have to pay for it before watching it. But you should make video of that kind so that you can use those videos for other purposes also after editing.
If you are making the content then never make a video without getting payment first.