Hi abhio38,
To reiterate, your GMAT score is based on not only the number of questions you answer correct/incorrect, but also the difficulty of those questions, among other things. Furthermore, when you take practice tests from companies other than GMAC, you may find some variation in algorithms used and thus variations in your score.
Rather than spending time worrying about the GMAC algorithm, you really should focus on the things you can control, and the number one thing you can control is getting better at the GMAT. If you get to a point at which you can dominate the GMAT, the specifics of the scoring algorithm won't matter because you will have the skills that you need to get an amazing score, right?
That being said, it may be difficult to improve your verbal score by 11 points in just two weeks. Are you able to take your GMAT a later date?
Lastly, you may find it helpful to read this article about
how to score a 700+ on the GMAT.
Feel free to reach out with any further questions.