U can get a replace blade from hard wares and fan shops also try ebay and oztion

Http://www.alibaba.com/product-gs/201959078/Fan_blades.html

According to Patton's frequently asked questions page you will need to contact a local authorised service centre.
http://www.pattonproducts.com/Faq.aspx
Here is a link to Patton's contact page, maybe they can tell you the whereabouts of your nearest service centre.
http://www.pattonproducts.com/ContactUs.aspx

Does it have a slight bend or a worst one.. generally these blades are quiet to replace... please tell us where u stay...