Hi Anirban,
I’m glad you reached out, and I’m happy to help. 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. So, there are a variety of possible reasons why your score has not improved from Q49.
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 to have the skills that you need to get an amazing score, right?
With that said, when is your GMAT and what is your GMAT score goal?