If I remember correctly, when I signed up for Astraweb I entered a username and password straight after payment. Did you?
If you did enter a username and password, go to http://www.news.astraweb.com/members_v2.cgi and login. You can find all the information there.
Astraweb is more of a budget NSP, so it's no surprise their support ain't that fast. Their actual news service is excellent though, worth the price atleast. It's much like when you're choosing an internet provider, if you pick the cheap one then you're going to have crap support. If you choose the expensive one, you'll get good support.