Bangla classes are going on very well in verbling.com.
What do you need for having a class:
Sign up for verbling.com. You need internet connection and 'google hangout'.
Very flexible. You can choose one class or a package of five classes. A package is cheaper. You can choose your days and time. The instructor's calendar is open for viewing.
No pressure to finish classes within a time period. Spread out your classes as you want.
Are the classes on real time or pre-recorded ?
The classes are on real time. You will have the same kind of intereaction as you have in real classroom.
Note: I am a very experienced Bangla teacher. I guarantee your success.