One must question, how long should I seek treatment for before I start to see overall progress. Now that answer obviously varies for every patient and type of injury but I am fairly certain that if you haven't seen overall progress in 2 years, then that type of treatment is not the answer for you.
I typically like to see some overall change in the patients progress in 4-6 weeks and if I am not seeing any change in progress, then I will refer the patient to a different type of treatment or practitioner.
As a patient, you should be asked what your goals are and what your expectations are. If you are not satisfied with your progress or if you are not sure what the expectations are, then you might need to seek another opinion.