BlueCross BlueShield rejects my claim for missing info, then references my claim form using the same info that was supposedly "missing"

I'm a case manager in rest homes/rehabs/skilled nursing facility.

I made sure my staff was charting to what the blue cross/shield book demanded.

I then fought to get our money from them for 2 years! They finally paid but Holy shit they didn't want to cover what they were supposed to.

If a health care facility has to fight that hard with knowledgeable people doing the fighting what chance do laymen have?