I called the call centre a few times and they were fairly helpful for simple questions. They clarified a few things and were able look up and confirm status of a few others things. The key thing to remember is that they are just front line support. Their expertise is limited to general information. The problem is people's expectations of them. People go to them for answers to questions they can't get answered in this forum. But if people on this forum can't help, it is likely the call centre reps can't help either. The one thing they can do outside of that is confirm some basic status like ("yes, we received your application on this date", or "yes, your oath ceremony is set for X date and time").