Usually this is deemed to be unfortunate but don't feel as if there is nothing you can do. There are a number of cases where a company has been "held to ransom" for their domain name, but cyber-squatting is becoming increasingly frowned upon.
The law is changing to protect people and companies that are under attack from such practices. If you need assistance to sue for your rightful name, email
support@nameyourweb.co.uk for a free appraisal of your position.