Complex sentence: Robbie plans an armed robbery at Price Slice and enlists the help of Finn and Callum, but Callum changes his mind and attempts to prevent the robbery but he is shot in the struggle.
Split into simpler sentences: Robbie plans an armed robbery at Price Slice and enlists the help of Finn and Callum. But Callum changes his mind and attempts to prevent the robbery but he is shot in the struggle.