You can always try eBay to see who's making them via 3D printers. Click here to see typical eBay link
Other options would be to check an authorized repair vendor in your area and see what they would charge to fix it.
Hi, you could try to get in touch with local dealer first to see if they are able to assist you.
Here you can find a local dealer: http://www.dji.com/where-to-buy