Need basic Facebook help for offline client

My offline client has had a facebook page since 2009 and they get negative comments which show up in the SERPS. I am not versed in how the basics work, Fanpage or Business page etc. so I don't know how to fix this. Ideally, it would be nice to continue to have a facebook page as it ranks high in the SERPS--this would be the only reason to keep it, but can we set it so people cannot post on there--only we can make posts. Also, if we can change a setting like that...can people still make posts on their own facebook page that will show up across all of their friends--that may be negative!

I don't think there is a big value in using facebook for customer acquisition for them as they are in the moving and storage business--usually a one time use--unlike a restaurant where folks eat out often. People tend to post something when a lamp gets broken and they are all pissed off--and more often than not--people will post negative comments, much more frequently than the positive comments.

Any suggestions... Change settings (I don't know what settings as I don't use FB--I have an account but it's not active---so I really don't know any of the settings)? Delete account...start a new account that no one can post too? I don't even know what they call it now...a Fan page or business page, etc. Please no comments about how the customer can use FB to answer and respond to issues--they do that personally...I simply need to know about how to get rid of the comments!
Thanks
Joe