Some major fashion brands have started charging for online returns, or even banning customers who routinely send products back. The companies say that growing levels of returns are hitting their profits, so just how costly is it to process an unwanted dress, and what really happens when we pop it back in the post?Evan Davis and guests take us behind the scenes into the hidden world of returns and the mini-industry that has sprung up to deal with the billions of pounds of items rejected by customers.It's a growing problem, according to many retailers, with a small number of customers causing particular damage, so what's the best way to tackle it and does the responsibility lie with brands, shoppers, or governments?Evan is joined by:Robert Kulawik, chief operating officer, Everything5pounds.com; Andy Rough, CEO, ACS Clothing; Dr Regina Frei, associate professor of digital economy, University of Surrey. PRODUCTION TEAM:Producer: Simon Tulett Researcher: Paige Neal-Holder Editor: Matt Willis Sound: Rod Farquhar Production co-ordinator: Rosie Strawbridge