Had a new health insurance plan during visits last year, but mistakenly gave the information for outdated insurance so the charges were not covered. After clearing up the mistake and having the right information, the current provider is not covering the previous charges

So am I just boned and have to pay the overdue balance myself or should I press the issue further and get their part covered? I understand if their policy changed during the time in between it could be complicated or impossible to get it covered retroactively, but if it's remained the same then I don't see why