It sounds from your description that you are doing all the "right things" for management of hypertension and cardio-vascular disease in general. If your blood pressure was confirmed to be a sustained hypertension by repeated readings then the use of a diuretic and calcium channel blocker as you described would be a reasonable treatment. There are a number of reasons for a physician to discontinue drug therapy and it depends on what you mean by "unwilling to renew".
Sometimes a pharmacist can't get a patient renewal because of administrative errors or problems of communication in the doctor's office. Other times, rejection for renewal may be strictly for appropriate medical reasons. Any physician who changes a patient's medical program because of medical reasons should communicate and explain the reasons to the patient. If you have not heard from your doctor about the reason or the reason you were given was confusing to you, you should make contact with your doctor and obtain an explanation that you understand. ..Maurice.