I use an agent because I can't be bothered to drive to Immigration, park the car near by, if I can, which often I can't, wait around for hours, often in the heat of the day, and then have to deal with their inconsistences. I also use one because I am happy to pay so that someone else does the stupid grunt work required. It's also why I have a cleaner, a gardener, a pool lady and a handy man, so that I can live my life in relative peace and laziness, doing the things I want to do, rather than have to do.