If nextgentel uses the same network adress plan for all of you, most likely they use NAT and have a fairly small adress span , it might very well be so that DAZ had been attaced by someone from the same adress span as you two are using, then someone at DAZ had blocked a adress span not single clients, this would affect ANY one on your adress plan, this is why u need to call the ISP and ask if THEY can connect, if they can't, it's affecting a whole adress span not specific clients.

By using Netstat or some window based GUI's for network connectivity test you can see what exact IP message you get from the timeouts, mind you it requers a bit of IP know how to understand the feedback you get, but your ISP should do this for you, ask to talk to a supervisor rather then the 15yo numb skull that usually picks the phone up when you first call them