Topcard, this is really vague, so I don't know how useful I can be. So I'm going to try to answer in the "primordial."
I think of customer service as a process and as having a structure. Customer service is not built upon smiling faces or voices or even courteousness at the very bottom of it--these are all clothing on the body, or skin to protect the organs. Customer service, for me, is built on the handling of information. Everything flows from that.
So, I would build a structure of blocks. If a block is moved (the person is not there for any reason), there is a different block to take that place.
I think I have already preached elsewhere some of the things that I am known for, like cross-training: "everybody has something to contribute'; "x is looking forward to learning y from you"....
But to return to the smiling voice: it is a fact that a smile during speech over the phone can be "seen" thousands of miles away. But that's an "extra."