Medicaid ran a credit report which indicated two insurance policies, neither of which we knew about. Contacting the insurance companies they said they had no record of these policies. They wouldn't say they had existed and been terminated on a certain date but rather that they did not show up in their systems. Medicaid indicates that is insufficient.
The report should give you a policy number and date of maturity. You go back to the insurance company. If the company continues to deny that such a policy ever existed, you go back to the credit reference agency and demand verification of their data.
Between the two of these organisations, you get in writing either verification of the data and the insurer's explanation of their failure (to keep records, to pay the right person, whatever has happened); or an admission from the credit reference agency of *their* error.
But somebody has f***ed up, and it isn't you.
Although... One other possibility... the credit report should show where the money was paid *to*. If it's an account you can identify, you may also be able to obtain relevant statements. Is it possible that it was paid and somebody, er, mislaid the payout and forgot about it? How far back are we going?
Meanwhile, go back to Medicaid, tell them what you are doing to resolve this issue, ask them what more you can do to resolve it, and impress on them the impact of their withdrawal of cover on a dying person. Leave them in no doubt that once you have established that your family is not responsible for the error that has caused this interruption you will see whoever IS responsible pilloried.
But be CALM and be POLITE. All you really care about is getting that care back in the house, preferably yesterday.
[P.S. When I say "you", I mean whichever family member is taking the lead, here.]