If you didn't sign anything, then there's an issue, a verbal agreement isn't good enough, they need to have signed forms of all their social actors/contributors, especially for a DVD being sold.
perhaps that's true in the UK, but it's not a legal requirement in the USA (although it's certainly wise for the DVD producer to get these things, just to protect themselves in situations like this one).......but we don't know where the OP lives, so maybe this would apply to him....or maybe not
Was the pic/video taken in a public place? I'm no lawyer, but I believe that makes a difference. Can you give us some more details about the circumstances......
you could be right. The circumstances could make quite a difference. It's hard to say without more info than the OP has given us