Domain fight

I created a Web Site using an Interface Program. I can work on this fast,without HTMl
Someone came in about the time my Web Site was do to renew, Grabbed it and Registered my Domain with another Domain place. I lost ownership of my Domain. Now How do I get my Domain back?
Does anyone have any Idea’s

The person did this on a resale program.

Yes someone can steal your Domain.
Why you say should I bother. Because My Domain is used by my business.