I am using sitemap.txt with a webmaster tools account; usually Googlebot spiders the updated sitemap within minutes after resubmission. Results in their index are normally visible after 2 - 7 days.
Try working on linking and navigation of your website. The webpages that are not indexed, check whether they are properly connected with the oter pages of your website. If yes then have some patience.. and when it omes to Google.. I can only say.. Patience is virtue...