Heads up about ghostwriter wants credit

I publish illustrative scenarios prepared by my practice. All participants and conversations are fictional. The fictional posts are not posts by real users, accounts of client experiences, or reports of actual results.
Illustrative scenario prepared by my practice.
For informational purposes only. This is not legal advice. Laws vary by jurisdiction. Consult a qualified attorney for advice specific to your situation.
Hypothetical question

Looking for advice on a legal issue. Here's what happened.

ghostwriter wants credit. I've been dealing with this for about 9 weeks now and the situation isn't improving.

The contract was signed 19 months ago. I am not sure I have the original signed copy. The total amount in dispute is approximately $84,000.

What are my legal options here? Is it worth pursuing?