Fighting with the Insurance Company

I've discussed this issue before, yet it seems to be a recurring problem. Until my daughters were born I could count on one hand the number of times I needed to call my health insurance company to question/dispute a claim. Since their birth... well, I lost track of the number of calls I've made.
For the first month after my daughters' birth, the hospital billed all their claims as "Baby A," "Baby B," "Baby C," and "Baby D," even though I named the girls the day they were born. So I spent months sorting out all the denied claims I received, all the while trying to convince the hospital to resubmit the claims with the girls' actual names. It took me until they were 1 1/2 to stop receiving bills from their birth.
Then this past January Hubby's employer switched its insurance carrier. The benefits are the same, but the service leaves a lot to be desired. Sue-Sue has a weekly physical therapy appointment to help with low-muscle tone issues. She receives this therapy through our local children's hospital, which is considered "in-network" by the insurance company. Yet every month I receive an explanation of benefits (and then a bill from the hospital) for hundreds of dollars because the therapy is incorrectly applied to Sue-Sue's deductible, rather than the straight co-pay we should be charged (which I pay at each appointment). Every month I call the insurance company, it's corrected and no one can tell me what the problem is. Yesterday I called to sort out the claims from April. The customer service representative actually said "I see you call about claims for Sue-Sue every month. Why is that?" Since I knew she wasn't responsible for taking care of the claims I simply laughed and said "I don't know. You tell me." First she tried to tell me that the hospital bills the therapy as an "outpatient" service rather than an "office" service, so she didn't know if the claims adjusters would even reconsider the claim. (WHAT??) Then she looked at our benefit terms and realized it didn't matter "where" the service took place as long as it was an in-network provider. She immediately transferred me to a claims adjuster who took care of the issue. This person told me he has no idea why the claims are being filed incorrectly, and warned me I should be prepared to call again next month.
I've always wondered what happens to the less informed in these situations. Certainly there are people who either a) don't know how to read an explanation of benefits, b) believe there is no way to dispute the explanation of benefits or c) simply don't read the forms and just pay what they're told. Taking care of my daughters' medical needs has taught me to read each and every form I receive and file them away for future reference.