Company Using my company name

Today I discovered a company that is using my company name. It is selling many of the same types of products. I first discovered them on facebook where they seem to be new this year. Looking at their domain which is very similar to mine it is new this year also. I'm not so worried about them competing with me, but more worried it could damage my company name. I don't think a serious business person would take somebodies company name like this so it could be a scam to customers or just provide really bad service. So what should I do now? Think I want to complain for Trademark infringement on facebook to hopefully get them removed, what other options do I have? Should I have a legal trademark for my company name? I have never bothered, but have been in business only since 2000 so obviously have the best claim to it. My company name is also a popular search term and I am the first result.