My line sound always busy

OK, I had this same problem, and had to make two calls to tech support (Panasonic)- here is a SUPER simple solution they gave me. Flip your phone set over, and using a paper clip or pen tip (something with a fine point) hit the little green 'reset' button which is on the bottom of the main base phone- look to the middle of the bottom on the left. Ta-dah!!! Now it should be fixed. All you will have to correct is your date and time on your base set. :)