I've bought from asos.com for 12 times since Sep 2013 to 2014. Female from Malaysia. Out of these many times only once have my delivery gone missing most probably due to local delivery or misplacement. Usually it takes about 2-3 weeks to arrive to Malaysia. After 5 weeks I didn't receive this particular order. When I wrote to asos customer service, they offered some advice to check with the local delivery. When I was sure that I knew it was lost they refunded me and also gave a 10% discount code for next purchase.
Overall I'm happy with my purchases as the quality of products are good and they always look true to image online.