Most cost effective way to use Study.com?

[Jonathan Whatley]

You can't take quizzes on Basic ($29.99/mo), though you can view video and written lessons. You can take quizzes and practice exams and view assignments on Premium ($59.99/mo), and your quiz progress will indeed be retained when you switch to College Saver ($235/mo). With College Saver you become eligible to take proctored exams, submit assignments, and receive college credit recommendations.

I do not have experience with refunds or credits for an unused part of a month on a lower level, but if it would help you it would be worth asking a customer service rep on Study.com about.