My guess is few people have experienced this because relatively few people on the board regularly ask to lower their credit limit and probably fewer still do it with Capital One because they don't have that many competing offers that this community is interested in (we are all card churners; some just play the game differently). Call Capital One. It could be that the SM agents just don't have the authority to reduce CL or it could be that your card has the minimum credit limit they allow for that particular card. In any event, it is hardly worth getting flummoxed over.