How to handle outstanding balance after being told by billing that my account is current with former insurance for services from 1.5 years ago

TLDR- today I just received a bill with outstanding balance from podiatrist from 1.5 years ago despite being told I have no balance and unclear how to handle.

In May 2023, I went to an in network podiatrist for an ingrown toenail, and I received consultation for inserts for my work shoes and was asked to schedule a follow up visit for the procedure. I then went back 2 more visits (4 total) for the insole fittings and a post op check in- healing was great. At the time of my visit, I had anthem Blue Cross Blue Shield, was on my family’s insurance and we had well exceed our deductible and had paid my copays for the visit.

A few weeks later, I checked on the anthem app and noticed I had several claims from them filed and I had a balance on the app I needed to settle. I called the office and spoke to reception and was told I was not marked for a balance and billing would call me if I needed to pay anything. Weeks go by, I never heard back, I left a voicemail and sent an email to the doctors office / billing and never heard back (after July 2023).

Fast forward to October 2024, and I get a bill dated to a few weeks ago for an outstanding balance for close to 800. I never heard from them since that I owed anything, nor was I contacted? Additionally, it shows that they still continued to charge my insurance for repeat claim attempts despite that policy ending on 9/1/23, and my family switched to Cigna before now I’m on my own Aetna policy.

Both the office and Anthem’s customer billing support line were closed after I got the bill in the evening, but my dad is suggesting I call anthem to have them straighten it out with the podiatrist. If the doctors / anthem are stubborn into not letting this slide I personally am going to attempt to negotiate this bill to atleast half due to the 1.5 years late communication.

My question is, should I handle this a different way? I’m just a little shocked that they didn’t try and contact me sooner for an outstanding balance of nearly 800?

About me: 25 Male, Northern Virginia area, pretax income ~95k