Managing The Relationship
Your goal throughout your flight training is to make steady progress through the training curriculum, which should cover all of the instructional requirements specified in FAR part 61, "Certification: pilots and flight instructors."
If you feel you are not progressing toward your goal, or truly are uncomfortable with the student-instructor relationship, talk to your instructor about the problem. Most likely the instructor senses it, too. The two of you should be willing and prepared to bring any problems into the open. As in any relationship, good communication is key to success.
Be honest in analyzing difficulties. Flight training is a partnership, and you as a partner have a responsibility to train consistently, be on time for scheduled lessons, and come prepared by having reviewed the appropriate material in advance of the lesson.
However, it's a tenet of flight training that a failure to learn reflects on the instructor. Training and experience prepare instructors to recognize problems that may be troubling their students. Instructors have an obligation to confront those problems, and attempt to solve them. A lack of progress in your training is a clear symptom that difficulties exist but are not being treated.
If your instructor isn't looking into the symptom to treat the cause, you must. Consider a lesson with another instructor. Even if it's just a temporary switch, another instructor may be what you need to jump start your stalled training.