My health insurer's claims system is broken

I have been trying to get covered out of pocket claims resolved for almost 6 months now but every time I call there is some issue that results in another 30 days of review. My doctor and I have both submitted the requested information multiple times but the phone reps say it was never submitted when we call in. My online portal shows the same claim 4 separate times with 4 different amounts listed for patient responsibility. I have another set of 2 claims of the same type where 1 shows the correct amount I owe while the other shows an incorrect number. It's clear to me that their system is horribly broken and I feel powerless. I have submitted a grievance but don't expect it will do much. Are there any other avenues available for resolution? Has anyone else had similar issues?