Sometimes needlework patterns aren't all that intelligible. You might want to drop by your friendly local yarn store and ask them to show you what you're doing wrong. As I understand it, the chain stitch is just the one loop to bring you up one round's breadth from the round you've just finished. And the ruffling might come from adding in too many stitches on a given round. Although ... You don't want this thing to be entirely flat either. It's supposed to be flat for a few rounds, then turn upwards and look bowl-shaped, then turn inwards again to close off the top. You want to add enough stitches to keep it growing flat at the bottom, then add fewer stitches for a couple rounds so it turns upwards, then reduce stitches to turn it inwards. Maybe you can even just work without the pattern, watch it grow and just make it grow in the shape you want row by row.