You will need to consult an attorney in your area and take two things for the consultation.
1) Take a copy of the insurance policies at issue.
2) Take a certified copy of the Invalidity of Marriage.
Invalidity of marriage is what many states refer to as annulment and basically states that you were never legally married (you know this). The problem here is that we are dealing with whatever your contract states with the insurance company (policy). It will take a careful review of the exact conditions listed in the policy to determine what specific conditions exist.
If the policy lists language requiring a "legal marriage" or even "marriage" then you could have your attorney write a letter to the insurance company that demanded your immediate reinstatement. If the policy had other language that permits them to cancel you then you will have to search for other options.
Assuming the policy speaks of "marriage" I think a basic analysis here leads to the conclusion that you were never married and therefore never breached the agreement with the insurance company. Therefore you would be entitled to have your policy reinstated. Understand that insurance companies do not make their money by granting benefits and paying claims... so you may have to sue them to get your benefits back.
The first step is to consult local counsel and have them thoroughly review your policy documentation. Your attorney may also wish to contact the treatment providers to let them know of the dispute so you will not have collection agencies harassing you.
Please reply if I can help further.
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