My mother's Medicaid coverage was recently denied. What should I do appeal, reapply or both?

My mother has lived in a Texas nursing home for several years with Medicaid long term care benefits. She was recently denied coverage because Medicaid requested proof of insurance by a certain date for private health care which she does not have. I did not realize at the time it was for private insurance so I inadvertently sent them her Medicare Advantage proof (which is not considered private insurance). They are claiming she was denied because documentation was not sent in a timely manner. I have spoke to Medicaid several times and told them she does not and has never had private insurance and they say the case is closed and to reapply.