Open Source License Compliance: 3D printing patented designs

EDIT: added more context below. I'm dealing with a situation and need some guidance.

3D printing patented designs. I've been dealing with this for about 2 weeks now and the situation isn't improving.

This involves content I created over the past 20 months. I do have documentation proving my ownership and timeline.

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

Real talk: just want to point out — the statute of limitations might be a factor here. In some states it's as short as 1-2 years. Don't sit on this too long fwiw.