Moving phone lines from one account to another

We paid Comcast $6000.00 to run Comcast  lines to out new location.  We've paid over $500.00 per month for the past 3+ years at the new location and our previous location.  We moved our offices last November to the  new location and requested to have our three business phone lines moved from the old location to the new.  Basically - after a period of time - we moved into the new location and sold the previous space.  

It is now February and we've been without our business phones for three months,  This week Comcast did however do something.  They disconnected our phone lines from the old location - some which we have had for over 30 years leaving us without any way for our clients or vendors to reach us.  They just receive a recording that the lines are no longer in service.  Notifying everyone that has these numbers of a new set of phone lines is an impossible task.  And we've been unable to get help with Comcast.  Is there anyone at Comcast that can help with this situation?  We've talked to probably more than a dozen representatives and been told everything you can imagine including multiple times that this was being handled as a priority within 24 to 48 hours.  This week we were told that the lines could not be moved until we signed a disconnect form which I was holding to be sure the lines were transferred first and not lost.  Given this information we reluctantly signed the form and the phones were disconnected leaving us without phone numbers for our business.  We've tried working with Comcast over the internet, by cell phone and even visiting the local service center.  It's impossible to get a response and it appears that the attitude is if Comcast puts it off long enough, maybe it will go away.

PLEASE HELP!!!