A Danish film on Netflix called, The Guilty.
Think Phonebooth or Buried in terms of an entire film based in one enclosed physical location.
Very tense, utterly engrossing. The premise, a chap on a '999' emergency call centre managing an incoming call. All focused on him.
One review I saw of a person having seen it in the cinema was that he 'had got to the end of the film and realised that he hadn't touched the beer he had bought.'
Best.