EDIT: And if that isn't a reasonable option, I can probably download a DRM-free version of the movie from some "movie preservationist".
Has anyone ever tried to sue Amazon in small claims court for a "disappeared" film? I guess Amazon will force arbitration, but you have a good case in arbitration. All you want is either: the original digital film, or a refund of original payment. This could be arbitrated very quickly since the sum is so small.
Also I believe MGM is still being operated Separately from Prime Video, or Amazon Studios so likely they would need to negate between the business units.
If it’s happened to you please call customer service and complain. If they can’t fix it or refund you, please get in touch with me and I will try and get it fixed for you
https://www.slashfilm.com/574053/amazon-sued-purchased-movie...