Are you short of time ? Do you want personal attention ? Studying by yourself with your own teacher might be the answer. It’s more expensive, but you can decide what happens in the lesson.
The teacher could help you with particular areas, such as Listening, or Pronunciation, or Writing. Or you might want to study the vocabulary you need for your profession. At the beginning of the course, the teacher will interview you to find out what your goals are. Every minute of every lesson will focus on those goals.