Hi gp2771,
GMAC has publicly stated that the Official Score that you earn on Test Day is within +/- 30 points of actual ability. Assuming a similar 'swing' in how your CATs function, your 3 most recent CAT score results show that you essentially performed the same each time (about 520 +/- a few points). As such, it's possible that you've gotten 'stuck' at this score 'level.' Raising these scores to a 630+ will likely require at least another 2 months of consistent, guided study - and you'll have to make significant improvements to how you handle BOTH the Quant and Verbal sections. By extension, you might need to consider pushing back your Test Date.
Before I can offer you the specific advice that you’re looking for, it would help if you could provide a bit more information on how you've been studying and your goals:
Studies:
1) How long have you studied? Did you study at all before starting your Course?
2) What study materials have you used so far besides the Course you named?
3) How have you scored on EACH of your CATs (including the Quant and Verbal Scaled Scores for EACH)?
Goals:
4) When are you planning to apply to Business School?
5) What Schools are you planning to apply to?
GMAT assassins aren't born, they're made,
Rich