Multiple no-show appointments

I have been trying to move our service to a new office location, but have had 2 no-show appointments in the past week, resulting in no progress being made to the actual setting up of services at the new office.

Wednesday 5/10, a tech actually showed up, found that the wires hadn't been pulled by the building as is needed, so no work was completed.  I'm unsure where blame lies on this one - the building and Comcast are supposed to be in contact before the appointment to confirm details, which clearly didn't happen.

Thursday 5/11, the tech was a no-show, and despite being on the phone with our dedicated representative, no one ever showed up. That same dedicated rep was completely unreachable the next day to help sort out the mess.

Saturday 5/13, the tech was a no-show yet again, and a representative claims he came to the building.  The front desk, manned by security personnel 24/7 and the video feed of the same lobby determined that was not true. The tech's notes describing the building were not even close to correct.

No one I've talked to has been willing/able to take responsibility for resolving this situation of repeated no-shows to appointments.  I would like to talk to someone who is capable of fixing this situation before I'm forced to waste more work hours waiting for a technician who fails to show up.

Edit: Comcast has also changed our termination date to be 10 days later without permission or input from our side. No options to reschedule this termination date to the original time set up are avaialable.

Edit 2: The appointment I was guaranteed was set up for this coming Tuesday 5/16 does not show up anywhere on our account. I am the primary account holder, so there should be no chance it doesn't show up if it was actually set up as I was told.