Business ProfileforNorth Carolina Oral Surgery Orthodontics

Hey team, I'm seeking help for a bill from North Carolina Oral Surgery Orthodontics. I started my Orthodontics treatment for open-bite issue since beginning of Jan 2021. The program price was about $5100, my dental insurance covering $2000 Orthodontics benefits. I made a one-time payment myself for the remaining when I started the treatment. My treatment ended in Aug 2022. However, I got a bill from North Carolina Oral Surgery Orthodontics asking for another $800 in May 2023. I called them for clarification. They told me because I changed my dental insurance for Year 2022 and the new insurance didn't have orthodontics benefits for 2022. But the payment between them and the insurance company was quartly payment not the one-time payment I chose. I asked them why they had never told me so that I'd keep my original insurance for 2022. The answer they gave me over phone was they only knew the insurance payment method after they initiated the claim. However, they never released this info to me through my whole treatment until I got this bill in year of 2023. They persisted that I needed to pay the full bill myself. But my point was it was not my full responsibility because how can they expect the consumer to understand the working model between them and the insurance company? Even if they expect consumer to understand it, they should have let me know in time after they knew it. They argued that they emailed me in July 2022 asking if I changed my insurance. I did received that email from them but the email still didn't told me because the payment with the original insurance was not ended yet. also the email was received after one and half year of my treatment, 7 months after I changed my insurance. if they let me know eariler, either I wouldn't change my insurance for 2022 or I can still changed back during my waiting period. I'd like to have your professional advice for this billing issue. thank you so much!