Since it is considered insecure, you cannot receive your password via telephone. If you have correctly entered your email in the e-application, you can change your login credentials; however, you can change the login credentials only for applications in the current admission round. If your application is not complete (and it has not been submitted yet), create a new one. Provided your application is complete and has already been submitted, you do not need your password any more since you can find all the relevant information on the entrance examination and results of admission procedures using this page (see the right section above).
IS AC allows its current and former users to administer the applications they have submitted from within itself. If you have forgotten your IS AC password, you must create a new application. You will be provided with a new IS AC password when enrolling in your studies, i.e. after being admitted.