Monarch Dental 1288 w main street lewisville texas dr charles chilcoat oral surgeon refuse to refund overpayment even though dental insurance says the owe me a refund lewisville Texas

hello; I will outline the keys steps with my COB insurance issue.  1.) I have a medicare advantage plan with MINOR dental benefits (Cigna) 2.) I have a Federal Dental plan with METLIFE which has most of the coverage 3. Dental office stated that maximum benefit would be from file medicare primary, Metlife secondary 4. After processing, the medicare plan paid very little BUT the office charged me according to their fee schedule which was $3116  5. ) The metlife plan is ALSO in network, After processing the met life plan stated I was overcharged by $937 for my up front cash payment. I have the EOB and a statement from the Metlife plan. 6.) The Dental office states that the fee schedule from cigna is the only one allowed 7.) The dental office refuses any refund whatsoever.   The dental office and Dr Chilcoat's staff state that they will not honor the in network fee schedule of the Metlife dental plan which they are In network with. The Office staff had suggested that I file the insurance through the medicare plan as primary payer to maximize my benefit. Now they state that the fee schedule through the metlife plan will not be honored and the medicare fee schedule is final. The medicare plan has only very minor coverage and is a free plan with my medicare advantage plan. I pay over $1000 per year for the metlife coverage and now they say I can not fully utilize those benefits because they filed medicare as primary.  They asked for payment up front and overcharged by using the cigna medicare fee schedule.  Now they refuse to honor the contractual agreement with the (in network) METLIFE plan.  Metlife has sent them a request for a refund of my overpayment. I can supply that request if needed.  

here is what the office stated . keep in mind that they actually sent the initial charges from their off to the metlife plan from their office and I have the fax. therefore an time they say they were not aware that I had a secondary insurance is an outright lie. here is the email response in quotes.  ", from what I am being told, Be cause we only had Cigna on file from the time of your extraction and bone graft and you submitted to Metlife on your own, according to the Cigna fee Schedule we collected correctly, and there is no Difference, we cannot reimburse you, because you have already been reimbursed by Metlife, and We cannot adjust fees after Claims were submitted by you individually. Metlife again was not primary at the time of your procedure, so we would have to base the cost off of Cigna".  It is all a scam to charge me more and to deny my right to fully utilize my high dollar IN NETWORK dental plan