I think it might depend when exacty you send the email, during the time of day, because I've had support replies within the hour aswell. Thats all I seem to hear about NameCheap support; You get an email reply with the hour, or you don't get one for about 24 hours!
I am curious to know how many support guys they have over there, because by the sounds of it, it's as if there is only a few. On addon, what are the chances these few support reps have to take your issue up with somebody 'higher' than them, who could handly any possible server problems with your account?
Dr.Pepper, may I ask what your issue is about?