Some using the domain I want

Let’s call my client NY Orthodontics (not the real name). They have two domains – nyorthodontics.com and nyortho.com (not the real domain names). My client is using nyortho.com for their website for brevity sake but bought both names to co-opt use of the other name to avoid a conflict. The domain nyorthodontics.com is forwarded to nyortho.com so anyone trying to go to that site will be redirected to nyortho.com. Unfortunately, there is a website named nyorthodontics.wordpress.com that comes up if I search for NY Orthodontics. It is a WordPress shell. I cannot find a company or organization called NY Orthodontics so it looks like someone just signed up with that name and never used it. Is there any way to get WordPress.com to take down the website or at least give me the information to contact the “owner”? I fear I will have to trademark my client’s logo, the name NY Orthodontics and the domain name to force them to shut it down but that can be a long and expensive process.