Coast Dental Services review: Overbilling, holding overpayments over 90 days

Documents substantiating this claim can be provided on request. I received services in March 2023 and again in April 2023 from the Lawrenceville, Georgia COAST DENTAL location. I paid $160 in March for a filling charge which later came up as just $47 owed by me after insurance. I was never told there was a "credit" for this overpayment on my "account." I only found out by accident in August. Unaware of what had occurred, I went back on April 17th and had several overlays done, which are billed as normal fillings with numbing. I was charged $732 at the time, which I was required to pay, despite Coast Dental already knowing CIGNA would pay 100% for fillings. I was unaware and paid in GOOD FAITH the $732 on my HSA Visa. Two days later I spoke to CIGNA who advised I didn't owe anything. Coast Dental never answers their phone for any reason, forcing me to go in person to the office to sort out or reverse the overpayment. I was told the "claims process" had to be completed, that my payments could not be reversed, and that I would be reimbursed in "two weeks." COAST said they had used the "wrong benefits chart" when creating my "estimate". This I later understood to be a lie. Unknown to me at the time also was the fact that they also made a routine, inexplicable (apparently planned) error on the claims form, ensuring the claim would be delayed or denied. I spoke to CIGNA again in June and was told that multiple requests had been made to Coast to correct the claims error but they were unable to contact them. Finally on July 5th I went BACK into the Coast office to sort out the error, which they denied. They tried to bully me into leaving, but I refused and stood there until the bookkeeper finally relented and went into her claims system, where the error and correction requests were clearly visible. The claims from April 17th were resubmitted (unwillingly by COAST) and finally processed on July 28th showing I had NO financial responsibility. I heard nothing from Coast despite having escalated the problems previously. So on August 4th I went BACK into the Coast office to get a final resolution. I was told not only that "people have been waiting for YEARS for refunds" but also "I do not work for you" when I asked that the employee call Coast corporate and followup on my previous problem escalation report. I was bullied, harassed, and demeaned, and my rights as a patient and consumer were violated. I am not the only person in Georgia that this has happened to.