See Mithun Articles
How to Reset Symantec Endpoint Protection Manager Console password in SEP 12.1
https://www-secure.symantec.com/connect/articles/how-reset-symantec-endpoint-protection-manager-console-password-sep-121
If above articles does not work please raised support ticket and received resetpass.bat file
How to create a new case in MySupport
http://www.symantec.com/docs/TECH58873
OR
Phone numbers to contact Tech Support:-
Regional Support Telephone Numbers:
- United States: https://support.broadcom.com (407-357-7600 from outside the United States)
- Australia: 1300 365510 (+61 2 8220 7111 from outside Australia)
- United Kingdom: +44 (0) 870 606 6000