My question involves a power of attorney in the state of: Florida

My grandfather recently died. Before he did, he applied for Medicaid and was put on "pending status", & a Medicaid provider began helping with his ALF bills as though he was approved. When applying, there was a page in the contract stating that if he was denied, he would have to pay back any money given. As his attorney-in-fact, I signed the papers with my name and then as POA for him. He passed away before he was approved for Medicaid and now the company wants their money back. I told them that they would need to file a claim against his estate, but they are trying to say that since I signed the papers, it is my responsibility to pay. Is this correct? I though that when I signed as POA I was signing on behalf of him, so it would be like him agreeing to pay them back, not me. What do I do?