Ok, so ASOS does *NOT* have a phone number, or live operators via instant messaging. They can't complete transactions for you, if you want to order over the phone or something. However, taking that into consideration, their customer service is very prompt.
I had a handful of snafus with my order at 2 AM, and had to stay up all night to make sure the items didn't go out of stock (one of which did). I contacted them on facebook multiple times, and I received a reply less than an hour later (usually within half an hour). They were very understanding, and did all they could to help. Although their email system is also pretty efficient, facebook would probably get you slightly faster answers.
I have yet to return anything from ASOS, but there are no restocking fees and shipping is free both ways--a rarity for online stores!
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