I am fairly new to this system. The dealer that sold us the system is no longer in business. One of my co lines is locked it is line 028 and I can't figure out on how to get it unlocked. It has happened before and the guy that sold the system had fixed it. Is it a matter of removing the extension where it is locked at or what. I am real lost any help would be appreciated. Remember I do not really understand this system. I do have the manuals but there is no refrence in there to this problem Thank you