Photography / Image Rights | client reselling my photography

Has anyone dealt with something like this? I'm not sure what my options are.

client reselling my photography. I've been dealing with this for about 7 months now and the situation isn't improving.

This involves software/code I developed over the past 28 months. I do have documentation proving my ownership and timeline.

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

I've dealt with this before.

I ended up filing with the appropriate government agency, which cost about $4-8 but saved me a lot more in the long run.