One thing that CenturyLink has done recently, at least in the Minneapolis/St. Paul area (although I doubt it is so localized), is to lay off a a bunch of installers/field techs, and then call them back to offer contractor job work at flat per job rates. So they have zero incentive to do anything more than the basic service.
They bought out Qwest here in the PNW, and I am using them for aDSL access without phone service. Their CS department is basically the same as Qwest, with the same phone number, same limited hours, same personnel, and same locations for the call centers.
They also still have the same problem of the right hand being unaware of what the left hand is doing.
In the numerous times I have had to call them about errors on my bill (which has consistently been once a month), the representatives have always been pleasant to interact with, even if, as has happened twice so far, nothing they said they were doing ever got done.