Not sure if you've explored this option or not, but VeritasPrep will let you take a verbal only prep course, which helps you save money over a full prep course (and time)...could be just the ticket to help boost your verbal score.

make a note of which types of verbal questions you are getting wrong (sentence correction, reading comprehension, or critical reasoning).

if you're getting mostly SC wrong, consider buying the manhattan gmat book for sentence correction. this is IMO the best book for this topic. also, it is generally agreed that improving SC is the easiest way to boost your verbal score.

if you're getting mostly CR wrong, then a good book to review is the powerscore logical reasoning bible (actually an LSAT book). i reviewed this a year back and the strategies are helpful in taking the GMAT

RC is generally thought to be the toughest section to improve in. other than reading more passages, reading the passages carefully, and not spending too much time on each question, there is not much else that can be said. others have proposed more advanced RC techniques that you can find if you search the forums.

Thanks for your suggestions & i really appreciate all,

But i already have Manhattan SC and read all the chapters but still not able to apply the logics when it came to solving the problem.

don't know how to improvize on it.

Still able to cope up with the CR & RC, but generally SC being the first few question in all the exams, my score is going down