I had the same problem, but because the phone comes with a 24 month warranty (Thanks, Samsung) I took it back to the CPH and they organised a rapid exchange. They'll get a refurbished phone sent out to you and swap it over with your broken phone. Turnover is about 24 hours.
Also, I explained the problem to the assisnt behind the counter, and lo and behold, when she went to check the phone, it was working.
Also, the phone is being delivered to the shop, so I got to keep my phone for the moment (handy for removing all data from it) and when CPW call me to let me know the replacement has arrived, I just take the current one in and swap them over.