It is possible that:
* You're misremembering the title: Double check the title and year of release.
* It's a lesser-known film: Search online film databases like IMDb for "Wragg" or variations of that word.
* You're thinking of a different film: Try to recall any other details about the film, like the genre or plot.
Once you have a correct title, you can easily find the cast information on IMDb or other movie databases.