If your supplication does not seem to be accepted by Allah Almighty then do not stop the supplication. Even in case of our beloved Prophet Mohammed, may Peace and Blessings of Allah Almighty be upon him, some supplications were accepted with some perceptible delay. Whose supplications can be more acceptable than his? Rapid or delayed acceptance is decided by Allah Almighty and as to the time of acceptance who can decide it better than Him?
( A common saying)