Yes, insurance is messy and can really really pisses you off.
Believe me, I've wanted to kill people when they told me that their doctors, whom have never met anyone in my family, know better than the doctors working with us.
I know if can be hard to ask for things also, but if you need the test, set up a go fund me. I'll donate $50.
When my daughter first started exhibiting issues a friend set up a go fund me. Members of IC gave $13K to help with the bills. I try to donate to every go fund me on IC since then. The people who helped can never be thanked enough. They will never know how much they impacted my life and helped my family.