Funny Money (1982)

Crime, drama. In Las Vegas, young Barry Nichols inadvertently steals a fortune from the Mob and is slashed to death by a limping hood. Later, his girlfriend Cass arrives in London with a stack of stolen credit cards looking for Ben Turtle, a talented pianist whose fingering is famous in the world of credit card crime. Their stormy relationship is hindered by hotel detective Keith Banks and assistant manager Diana Sharman. -- BFI synopsis from http://www.bfi.org.uk/films-tv-people/4ce2b69480238