Dental insurance problem - am I liable?

My dentist advised me that I required two crowns. The office manager advised me that he had contacted my dental insurance company and they had agreed to pay a certain amount and asked me to pay approxinmately 30% co-pay. I agreed to this and the work was completed. In my belief I fulfilled my part of the verbal contract with the dentist to pay my co-pay. Some weeks later my insurers claimed they had not authorized porcelain crowns and refused to pay their portion. The dentist now expects me to pay this amount. I spoke to the insurers and they agreed that they had erroneously authorized the dentist ,and that they should resubmit the bill and it would be paid. the dentist did this, but the insurer still refuses to pay. I do not feel that I should be expected to pay this portion, due to a mix-up between the dentist and insurer. I fulfilled my part of the payment, and was not advised that I would have to pay if the insurance did not. How should I proceed?
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Unfortunately, you ARE liable for anything not covered by your insurance-even if the dentist's office was quoted a verbal benefit, this is not binding. It is your responsibility to know what coverage you have and what the insurance requires for that benefit to be paid. Your only out is to contact your insurance company and find out what the appeal process is. You will probably have to submit this in writing. If in the appeal process, it is determined that the dentist's office did not follow the authorization procedure required by the insurance, you may be able to request that the dentist's office reduce the portion you owe, but they are not required to reduce their charges, and chances are, you have signed something (probably the first time you were seen) that states that you are responsible for payment of services rendered, insured or not.
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