Seth Godin gives us something to think about in his post Starting Over With Customer Service. In it, he suggests that customers would be willing to wait a day or two for amazing service from a well-trained agent who knows how to research and resolve an issue. Would this be preferable to interminable waits on hold with a rep who can't help you right now, or worse, can't even understand what you want?
Personally, I don't see why we can't have quick service that's amazing to boot! It means more well-trained customer service reps supported by the appropriate processes and technologies, but if you pencil it out, you may find it costs less than turnover, call-backs, and disgruntled customers. Check out Seth's post and then let me know your thoughts.