You might think a play that lurks behind the scenes of an Oxford Street sportswear store, to eavesdrop on security and sales staff labouring in the Christmas rush, would be no great laughing matter. Yet while Levi David Addai’s play remains obstinately plot-lite, its undercurrents of comedy and pathos keep the 85-minute evening buoyant.

For Addai’s mainly young characters at the Total Sports store, not unlike those relentless hopers and wistful dreamers in Chekhov or Tennessee Williams, aspire to make something of their lives and escape. They want more than regimented drudgery at just over £6 per hour in retail will ever give them.

“Hi, believe I can fly. Spread my wings — fly away,” ridiculously sings Emmanuel, the 53-year-old Ghanaian loss prevention manager, who secretly reads up on business management as if he could ever get into it. The only one taking his job half-seriously is Alek, brought to lovely comic life by Kristian Kiehling, all wreathed in officiousness, pedantry and impassive gloom as the young, Polish security guy, immersed in the Daily Mail.

Here, then, is one of those theatrical snap-shots of London today, of its hustled, multi-cultural servant-class, who cater to a nation of shopping addicts. A single plot-line is traced through the experience of Nathaniel Martello-White’s dejected Kofi, a young black Londoner who achieved a university degree and wants to hack his way into journalism but somehow remains trapped at Total Sports.

The arrival of old schoolmate, Darrell Obi-Anderson, whom Ashley Waters endows with an air of smiling, nonchalant menace, proves dangerous. Not only does Darrell threaten Kofi’s fragile romance with Preeya Kalidas’s theatre-mad Loraina but the newcomer also forces him to choose between turning a blind eye to criminality or exposing it.

In the cruel, believable resolution Kofi emerges as victim and fall-guy, aware that he dare not tell the truth. “Be a winner, not a sinner,” an Oxford Street pamphleteer urges him as he leaves. It is surely Addai’s intention to suggest that in the service industry today the shameless, artful sinner wins out.

Dawn Walton’s environmental production, fortified by Soutra Gilmour’s neat design, converts the theatre into a sports shop. The audience sit on stools. Narrow vertical and horizontal playing areas bisect the square auditorium. It all feels authentic. If only Addai had probed more deeply, Oxford Street would be a more exciting theatrical thoroughfare.

Until 31 May (020 7565 5000, www.royalcourttheatre.com)