Neighbor Billing Me $14k For A Tree Fallen In A Blizzard

I live in Iowa and we had a nasty blizzard with high winds and a big branch on a tree in my front yard fell into my neighbors yard. I was out of town but I saw it on my ring camera. When I got home a few days later they had already removed the piece that was in their yard. They re-sided their entire house and detached garage and now their insurance company is trying to come after me for $14,000. I called them and provided my home insurance information and told them when it initially happened I was told I was not liable since it was a storm/act of god. Then they sent another bill in the mail. I called again and they said they didn’t have my insurance information so I gave it to them a second time. Now they’ve just sent me the bill again and I don’t know what to do. I called my insurance and they didn’t receive a claim. Do you think I need a lawyer? The tree did NOT fall on their house it was in their front yard and when I had someone go look at the tree when it first fell they confirmed it didn’t hit any houses.