It seems like there are lots of changes afoot in SC with regards to control channels for Palmetto 800 sites. When I was through Columbia this past weekend, Harbison, Richland Simulcast and Lexington Simulcast sites were on alternate CCs. The N. Augusta site was reported to be using a different CC in the last week or so. I assume this has to do changes associated with Rebanding.
Check the alternates first (if any are listed), then check all the sites' frequencies. Then do a band search.
If anyone else has noticed control channels that have changed, please post them.