I recently went through the Cubex not responding issue myself. Here's the trick:
Call their number, let it ring until the phone company times it out and disconnects you.
Call Back and let it time out again.
Repeat until Roger answers (took about 20 times).
Not sure what the problem is, but over on QRZ, there's a thread I started that also contains another Ham who had the same experience. We both eventually got our antennas, and are both very happy with them, but the excuses were rather transparent (if you know what I mean).