Thank you for your suggestions! I am so sorry you have been a victim of the red-tape of the health insurance system. This denial for "pre-existing" stuff for aftercare is very scary, and I wish you the best. I thought that when you switched insurance through an employer, without a gap in coverage, that shouldn't happen. I certainly hope you will win this fight!
I am still pre-treatment, but not for long. I have been tenacious in calling BC and asking questions for more than a year. Since the answers vary a bit with each person I speak to (not to mention a change in our coverage for 2010!), I've kept a log of my calls, and keep calling. Finally I seem to have ironed out some things. There is a lot they won't tell you unless you specifically ASK about it using their "healthcare" terminology (which, of course, you don't KNOW when you begin), but I have learned alot through all the calls. The in-and-out-of-network stuff gets very complicated. You're very right that the health care coordinator at one's place of employment is a good initial advocate for guidance on how to proceed.
For newbies, talk to some doctors billing offices. They can't get very specific about your case unless you have scheduled treatment, but you will learn some things that may guide you to ask even better questions of your insurance company. Learn as much a you can ahead of time. In the beginning, I can't tell you how many people said "Oh - you can't think of money when it comes to your health". That is SO incorrect! You can call a doctor's billing office, and get the codes and charges for the procedures. Then you can call your insurance company to find out about your coverage. (the doctors won't discuss it; don't have the time OR the info). I am warning all my friends to study their policies while they have no health issues going on, and make any improvements/changes to their coverage before they have some big health issue come up! Then, be careful about the regulations/time frames on coverage for those changes. So many people don't understand the impact of coverage for specialists, or in-vs-out-network coverage, co-insurance, co-pays, deductibles, etc.
Thanks again, and I hope you are successful in rectifying that gap in coverage!