Outbound Caller ID

We have 5 general unassigned lines for the office.  

Outbound caller ID shows our company name for two of them, just the number for a third and the last two show an individual's name  for each line - individuals we do not know.  

Multiple customers have called back asking for these individuals and become concerned they are being spoofed or just do not pick up our calls.  

We have tried to fix this before without ever reaching a solution.  We need the outbound caller ID to be our company name on all lines.  We have already reassigned the outbound phone ID number to our main number, which only solved the problem for our second line - not lines 3 - 5.  We have been working with Comcast on this issue for about 12 months with no resolution.