Trademark Dispute: AI art used without permission

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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

English isn't my first language so bear with me. I'm dealing with a situation and need some guidance.

AI art used without permission. I've been dealing with this for about 9 weeks now and the situation isn't improving.

This involves content I created over the past 25 months. I do not have documentation proving my ownership and timeline.

Has anyone been through something similar? What worked for you?

Illustrative response

Copyright registration isn't required but it helps a lot with damages.