Well, I'm not sure exactly how much time you have put into prep, but if you are coming in short of your goals, the short answer is, you must put in more time. For every official GMAT test, you should probably be taking five or six prep tests and practicing problems outside that as well leading up to the exam. If you took your prep course with Veritas, you can retake the course until you get a score with which you are satisfied. Other companies may have similar guarantees--check out yours to see. Some people find it's simply not worth the time required to get the score they want, but in a competitive year like this one, I would argue it's well worth the time to get that extra bit on your score.