Voice - Lines not rolling over properly
We have (7) lines. When line one is busy, the next caller gets a busy signal. The same thing happens on line 3. When lines 1-3 are busy, the caller gets a busy. Lines are not rolling over as they should. Also, line 1 & line 3 have broken dial tone as though we have a voicemail message. We do not have Comcast Voicemail.