The right to work in the portfolio?

Question

Copyright

Hello. I recently made a website for a Moscow company, and as a result, it turned out that I worked through an intermediary who claimed that he was a representative of this company. After he disappeared.
I called the company to give away the site and get my money. As it turned out, they broke the contract with this intermediary.
They demand from me that I remove the site from the portfolio, or the court.
Their comment

If you add screenshots of the site to your portfolio, we, on the legal grounds specified in the contract, will go to court for the illegal use of something that does not belong to you.

I didn't sign anything with them. Didn't contact at all. I personally made the site, so they are trying to squeeze out my intellectual property?
Please help me to solve the issue