You may have to retain a lawyer and sue them to recover your damage.
Most lawyers will give you a free consultation if you ask for one. We do this all the time, but remember that our time is valuable and you should stay with the people who help you the most.
A review of your policy will need to be conducted. Sounds like they are trying to deny based upon improper notice. I would suggest contacting an attorney to discuss your options.
The response to this inquiry does not establish an attorney client relationship.
You should retain an attorney to assist you in fighting with the insurance company. If they continue to deny your claim you may have to file a lawsuit for a Declaratory Action or Bad Faith.