my unlocked blackberry storm has a "cold"

[congestion]

I just got an unlocked blackberry storm and am using AT&T service on it. I used a program and it worked making it fully functional,well for the most part. I can get and send SMS and MMS and use my internet. My problem is that I can't get calls,make calls,or check voicemail. It says "CONGESTION" But here's the tricky part...if I'm at my parents house or school I can get calls,make calls,and check my voicemail. So my question is why is it like that and what do I have to do to make calls work all the time no matter where I am. (Note: it's not AT&T service I get good service using them...I'm guessing it's more in the settings or service books) HELP PLEASE!