When I did Comcast phone support it was common to have different call centers and queues for different regions, each region has different internal tools owing to differing networks during acquisitions so only agents with the right tools and accounts would be able to handle certain customers. Our center handled multiple regions but agents would usually be trained to handle just one. Usually the IVR will make cursory account billing and outage checks and then forward the call to the appropriate location.
I also had the displeasure of working for Comcast in phone support before I went back to school and this is definitely part of the reason.
Multiple completely different decrepit and kafkaesque billing systems because they were too lazy or incompetent to properly migrate customers over to a unified modern one. IMO, one of the reasons Comcast has had notoriously bad customer support is because their internal systems were so complicated that even reps who wanted to help might have just given up and told you they fixed the issue to get you off the phone.
