I know how much it is difficult to speak English language by non native English speakers. It is very difficult to correct the mistakes in one's pronunciations for non native speakers. Although there are many colleges and schools which provides courses for accent reduction but due to shortage of time and their high charges it is not feasible for most of the people to go for such courses.
But now there have come some good English language online institute like Executive Language Tutors (executivelanguagetutors.com) who provide
online accent reduction classes to refine the accent and pronunciation of non native english speakers. Their teachers are excellent in accent reduction coaching with years of good experience.