From the time an application for approval of a subdivision or land development plan, whether preliminary or final, is duly filed as provided in the Subdivision and Land Development Ordinance, and while such application is pending approval or disapproval, no enactment or amendment of this chapter shall affect the decision on such application adversely to the applicant, and the applicant shall be entitled to a decision in accordance with the provisions of this chapter as it stood at the time the application was duly filed. In addition, when a preliminary application has been duly approved, the applicant shall be entitled to final approval in accordance with the terms of the approved preliminary application as hereinafter provided. However, if an application is properly and finally denied, any subsequent application shall be subject to the intervening change in this chapter.