Xolair Being Denied By Insurance?

I got a call last month from my provider saying my Xolair was approved - made an appt for the injections. I then called to ask what my co pay/ amount would be and got a message not to come for my appt and that it *hasn't* been approved. I am so confused. They say it's been denied twice and is now being appealed.

I have an angioedema diagnosis for over 7 years. I have been on singulair, two doses of Allegra, two doses of Zytrtec daily for over 8 years. I am covered in hives and rashes every day for over a year without my medications working. I've had allergies/asthma diagnosed since I was 7 and I'm now 41.

I've been trying to get information from my dr office on why with this level of information, I'm being denied as I thought the requirement was that to get Xolair you had to fail all other treatments (which I have).

Any advice or tips anyone can share? I have really good insurance and I've never had any issues getting any other procedure/med covered.