Complex sentence: The last episode of the series aired on 18 September 2011 and the show never returned in 2012, there have been no casting calls or application details released by the BBC for a fourth series as of August 2017.
Split into simpler sentences: The last episode of the series aired on 18 September 2011 and the show never returned in 2012. There have been no casting calls or application details released by the BBC for a fourth series as of August 2017.