Illegal use of intellectual property

I've been fighting for over a year now for the above-mentioned company to discontinue use of my work. I was approached by a designer by the name of Anasvan Poolchand who is now claiming my work was never approved but to my surprise my work is being used by the company http://www.worldwideworx.com/wp-content/uploads/2020/10/Cloud-in-Africa-2020c.pdf . I did a few jobs with the mentioned individual and was never paid for even one of them but just never had proof if my work was being used. I've sent multiple emails to WorldWideWorx asking them to stop using my work without my permission and no one ever responds. It really surprises me how these big companies do as they please because they have money to pay expensive lawyers.