Insurance woes

My employer switched us to Aetna insurance at the beginning of the year, and it has been a giant pain-in-the-ass the entire time. I'm thankful for the fact that they allow me to have a Certified Nurse Midwife (CNM) as my primary care provider, and they are paying for my birth center birth (at least I hope), rather than a traditional hospital birth. However, I have had nothing but problems with the claims that have been filed to date. They are refusing to pay for my 20-week ultrasound despite THREE customer service reps telling me that it is covered under my insurance policy at 90%. Ever step I take is a battle. I have considered switching to Mr. Savvy's insurance, and paying the additional premium for foregoing my own insurance, but then it's like rewarding my employer for providing crappy insurance. On top of that, Aetna administers our FSA plan as well. The $1,000 bill they won't pay for the ultrasound is also denied as FSA because of the fact that it was denied by my Aetna medical insurance. So not only do I owe $1,000, but I have to pay it with post-tax dollars?!?! Sounds like a scam to me. I have had no special treatments this pregnancy. Prenatal visits every four weeks, I opted to skip any extra tests or screenings, with the exception of the ultrasound. Nothing out of the ordinary, no additional costs. As a matter of fact, a midwife-assisted pregnancy and birth costs less than half that of an OB/GYN assisted pregnancy and birth. Update: I just spoke with the ultrasound provider and the woman in the business office said that they have never had Aetna pay an ultrasound claim. She said the next step is to file a formal appeal with Aetna, and then a complaint with the Wisconsin Office of the Commissioner of Insurance. Unfortunately, she said this is all standard procedure.