A Chinese national with a visa that expired two years ago was among 21 people arrested by Chandigarh police’s cyber crime cell on Sunday for running a fraudulent app-based quick loan service that extorted money from dozens of people after threatening them with reputational harm.The police named 34-year-old Chinese national Wan Chengua as the kingpin of a racket that operated a number of instant loan mobile applications. The racket was busted following a 10-day operation spanning five states, including the Delhi-NCR region, Rajasthan, Bihar and Jharkhand. Most of the arrests took place around the national Capital. “Wan Chengua is the…