Something similar happened to me with a trademark.

I used a made-up word in a story I wrote in the mid 1990's. In 2010, a company happened to make up that same word and trademark it. Sometime after that, they found my story and demanded that I remove it.

Ridiculous. Obviously I had usxed it long befor e they had and the Wayback machine proved it. Nor was I attaching thatr word to any product - it was just in my story!

It was in no way worth fighting over: I made up a diferent word and edited my story.