New, non-3G wireless home phone (IFWA-40) is not taking or sending any calls

I have wireless home phone, and was sent the new IFWA-40 to replace the old 3G unit. That's fine. Technology moves on. So I set it up and hooked up the cordless phones. They all get a lovely dial tone. So far, so good.

The trouble arises when we try to make a call or someone tries to call us. From our end, "the call [we] are attempting to place is not allowed from this line." Incoming callers are told that we "have a voicemail box that has not been set up yet." (I believe this to be untrue; I set the IFWA-40 to answer calls, although there was no instruction explicity stating messages would be taken.)

I have tried all the troubleshooting, and my account has not been suspended. I have googled and googled, and nobody has the answer to this problem. 

 We need this line due to reasons. Anyone got any ideas? If so, thanks very much in advance.

Gus